From dccf4a48d47120a42382ba526f1a0848c13ba2a4 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Sat, 17 Dec 2005 17:58:46 -0500
Subject: [PATCH] UHCI: use one QH per endpoint, not per URB

This patch (as623) changes the uhci-hcd driver to make it use one QH per
device endpoint, instead of a QH per URB as it does now.  Numerous areas
of the code are affected by this.  For example, the distinction between
"queued" URBs and non-"queued" URBs no longer exists; all URBs belong to
a queue and some just happen to be at the queue's head.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/usb/host/uhci-debug.c | 320 ++++++++++++------------------------------
 1 file changed, 92 insertions(+), 228 deletions(-)

(limited to 'drivers/usb/host/uhci-debug.c')

diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c
index 5832953086f..3faccbd6854 100644
--- a/drivers/usb/host/uhci-debug.c
+++ b/drivers/usb/host/uhci-debug.c
@@ -90,13 +90,60 @@ static int uhci_show_td(struct uhci_td *td, char *buf, int len, int space)
 	return out - buf;
 }
 
-static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
+static int uhci_show_urbp(struct urb_priv *urbp, char *buf, int len, int space)
 {
 	char *out = buf;
-	struct urb_priv *urbp;
-	struct list_head *head, *tmp;
 	struct uhci_td *td;
-	int i = 0, checked = 0, prevactive = 0;
+	int i, nactive, ninactive;
+
+	if (len < 200)
+		return 0;
+
+	out += sprintf(out, "urb_priv [%p] ", urbp);
+	out += sprintf(out, "urb [%p] ", urbp->urb);
+	out += sprintf(out, "qh [%p] ", urbp->qh);
+	out += sprintf(out, "Dev=%d ", usb_pipedevice(urbp->urb->pipe));
+	out += sprintf(out, "EP=%x(%s) ", usb_pipeendpoint(urbp->urb->pipe),
+			(usb_pipein(urbp->urb->pipe) ? "IN" : "OUT"));
+
+	switch (usb_pipetype(urbp->urb->pipe)) {
+	case PIPE_ISOCHRONOUS: out += sprintf(out, "ISO"); break;
+	case PIPE_INTERRUPT: out += sprintf(out, "INT"); break;
+	case PIPE_BULK: out += sprintf(out, "BLK"); break;
+	case PIPE_CONTROL: out += sprintf(out, "CTL"); break;
+	}
+
+	out += sprintf(out, "%s", (urbp->fsbr ? " FSBR" : ""));
+	out += sprintf(out, "%s", (urbp->fsbr_timeout ? " FSBR_TO" : ""));
+
+	if (urbp->urb->status != -EINPROGRESS)
+		out += sprintf(out, " Status=%d", urbp->urb->status);
+	out += sprintf(out, "\n");
+
+	i = nactive = ninactive = 0;
+	list_for_each_entry(td, &urbp->td_list, list) {
+		if (++i <= 10 || debug > 2) {
+			out += sprintf(out, "%*s%d: ", space + 2, "", i);
+			out += uhci_show_td(td, out, len - (out - buf), 0);
+		} else {
+			if (td_status(td) & TD_CTRL_ACTIVE)
+				++nactive;
+			else
+				++ninactive;
+		}
+	}
+	if (nactive + ninactive > 0)
+		out += sprintf(out, "%*s[skipped %d inactive and %d active "
+				"TDs]\n",
+				space, "", ninactive, nactive);
+
+	return out - buf;
+}
+
+static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
+{
+	char *out = buf;
+	int i, nurbs;
 	__le32 element = qh_element(qh);
 
 	/* Try to make sure there's enough memory */
@@ -118,86 +165,36 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
 	if (!(element & ~(UHCI_PTR_QH | UHCI_PTR_DEPTH)))
 		out += sprintf(out, "%*s  Element is NULL (bug?)\n", space, "");
 
-	if (!qh->urbp) {
-		out += sprintf(out, "%*s  urbp == NULL\n", space, "");
-		goto out;
-	}
-
-	urbp = qh->urbp;
-
-	head = &urbp->td_list;
-	tmp = head->next;
-
-	td = list_entry(tmp, struct uhci_td, list);
-
-	if (cpu_to_le32(td->dma_handle) != (element & ~UHCI_PTR_BITS))
-		out += sprintf(out, "%*s Element != First TD\n", space, "");
-
-	while (tmp != head) {
-		struct uhci_td *td = list_entry(tmp, struct uhci_td, list);
-
-		tmp = tmp->next;
-
-		out += sprintf(out, "%*s%d: ", space + 2, "", i++);
-		out += uhci_show_td(td, out, len - (out - buf), 0);
-
-		if (i > 10 && !checked && prevactive && tmp != head &&
-		    debug <= 2) {
-			struct list_head *ntmp = tmp;
-			struct uhci_td *ntd = td;
-			int active = 1, ni = i;
-
-			checked = 1;
-
-			while (ntmp != head && ntmp->next != head && active) {
-				ntd = list_entry(ntmp, struct uhci_td, list);
-
-				ntmp = ntmp->next;
-
-				active = td_status(ntd) & TD_CTRL_ACTIVE;
-
-				ni++;
-			}
-
-			if (active && ni > i) {
-				out += sprintf(out, "%*s[skipped %d active TDs]\n", space, "", ni - i);
-				tmp = ntmp;
-				td = ntd;
-				i = ni;
-			}
+	if (list_empty(&qh->queue)) {
+		out += sprintf(out, "%*s  queue is empty\n", space, "");
+	} else {
+		struct urb_priv *urbp = list_entry(qh->queue.next,
+				struct urb_priv, node);
+		struct uhci_td *td = list_entry(urbp->td_list.next,
+				struct uhci_td, list);
+
+		if (cpu_to_le32(td->dma_handle) != (element & ~UHCI_PTR_BITS))
+			out += sprintf(out, "%*s Element != First TD\n",
+					space, "");
+		i = nurbs = 0;
+		list_for_each_entry(urbp, &qh->queue, node) {
+			if (++i <= 10)
+				out += uhci_show_urbp(urbp, out,
+						len - (out - buf), space + 2);
+			else
+				++nurbs;
 		}
-
-		prevactive = td_status(td) & TD_CTRL_ACTIVE;
-	}
-
-	if (list_empty(&urbp->queue_list) || urbp->queued)
-		goto out;
-
-	out += sprintf(out, "%*sQueued QHs:\n", -space, "--");
-
-	head = &urbp->queue_list;
-	tmp = head->next;
-
-	while (tmp != head) {
-		struct urb_priv *nurbp = list_entry(tmp, struct urb_priv,
-						queue_list);
-		tmp = tmp->next;
-
-		out += uhci_show_qh(nurbp->qh, out, len - (out - buf), space);
+		if (nurbs > 0)
+			out += sprintf(out, "%*s Skipped %d URBs\n",
+					space, "", nurbs);
 	}
 
-out:
 	return out - buf;
 }
 
-#define show_frame_num()	\
-	if (!shown) {		\
-	  shown = 1;		\
-	  out += sprintf(out, "- Frame %d\n", i); \
-	}
-
 #ifdef CONFIG_PROC_FS
 static const char * const qh_names[] = {
+  "skel_unlink_qh", "skel_iso_qh",
   "skel_int128_qh", "skel_int64_qh",
   "skel_int32_qh", "skel_int16_qh",
   "skel_int8_qh", "skel_int4_qh",
@@ -206,12 +203,6 @@ static const char * const qh_names[] = {
   "skel_bulk_qh", "skel_term_qh"
 };
 
-#define show_qh_name()		\
-	if (!shown) {		\
-	  shown = 1;		\
-	  out += sprintf(out, "- %s\n", qh_names[i]); \
-	}
-
 static int uhci_show_sc(int port, unsigned short status, char *buf, int len)
 {
 	char *out = buf;
@@ -321,139 +312,29 @@ static int uhci_show_status(struct uhci_hcd *uhci, char *buf, int len)
 	return out - buf;
 }
 
-static int uhci_show_urbp(struct uhci_hcd *uhci, struct urb_priv *urbp, char *buf, int len)
-{
-	struct list_head *tmp;
-	char *out = buf;
-	int count = 0;
-
-	if (len < 200)
-		return 0;
-
-	out += sprintf(out, "urb_priv [%p] ", urbp);
-	out += sprintf(out, "urb [%p] ", urbp->urb);
-	out += sprintf(out, "qh [%p] ", urbp->qh);
-	out += sprintf(out, "Dev=%d ", usb_pipedevice(urbp->urb->pipe));
-	out += sprintf(out, "EP=%x(%s) ", usb_pipeendpoint(urbp->urb->pipe), (usb_pipein(urbp->urb->pipe) ? "IN" : "OUT"));
-
-	switch (usb_pipetype(urbp->urb->pipe)) {
-	case PIPE_ISOCHRONOUS: out += sprintf(out, "ISO "); break;
-	case PIPE_INTERRUPT: out += sprintf(out, "INT "); break;
-	case PIPE_BULK: out += sprintf(out, "BLK "); break;
-	case PIPE_CONTROL: out += sprintf(out, "CTL "); break;
-	}
-
-	out += sprintf(out, "%s", (urbp->fsbr ? "FSBR " : ""));
-	out += sprintf(out, "%s", (urbp->fsbr_timeout ? "FSBR_TO " : ""));
-
-	if (urbp->urb->status != -EINPROGRESS)
-		out += sprintf(out, "Status=%d ", urbp->urb->status);
-	//out += sprintf(out, "FSBRtime=%lx ",urbp->fsbrtime);
-
-	count = 0;
-	list_for_each(tmp, &urbp->td_list)
-		count++;
-	out += sprintf(out, "TDs=%d ",count);
-
-	if (urbp->queued)
-		out += sprintf(out, "queued\n");
-	else {
-		count = 0;
-		list_for_each(tmp, &urbp->queue_list)
-			count++;
-		out += sprintf(out, "queued URBs=%d\n", count);
-	}
-
-	return out - buf;
-}
-
-static int uhci_show_lists(struct uhci_hcd *uhci, char *buf, int len)
-{
-	char *out = buf;
-	struct list_head *head, *tmp;
-	int count;
-
-	out += sprintf(out, "Main list URBs:");
-	if (list_empty(&uhci->urb_list))
-		out += sprintf(out, " Empty\n");
-	else {
-		out += sprintf(out, "\n");
-		count = 0;
-		head = &uhci->urb_list;
-		tmp = head->next;
-		while (tmp != head) {
-			struct urb_priv *urbp = list_entry(tmp, struct urb_priv, urb_list);
-
-			out += sprintf(out, "  %d: ", ++count);
-			out += uhci_show_urbp(uhci, urbp, out, len - (out - buf));
-			tmp = tmp->next;
-		}
-	}
-
-	out += sprintf(out, "Remove list URBs:");
-	if (list_empty(&uhci->urb_remove_list))
-		out += sprintf(out, " Empty\n");
-	else {
-		out += sprintf(out, "\n");
-		count = 0;
-		head = &uhci->urb_remove_list;
-		tmp = head->next;
-		while (tmp != head) {
-			struct urb_priv *urbp = list_entry(tmp, struct urb_priv, urb_list);
-
-			out += sprintf(out, "  %d: ", ++count);
-			out += uhci_show_urbp(uhci, urbp, out, len - (out - buf));
-			tmp = tmp->next;
-		}
-	}
-
-	out += sprintf(out, "Complete list URBs:");
-	if (list_empty(&uhci->complete_list))
-		out += sprintf(out, " Empty\n");
-	else {
-		out += sprintf(out, "\n");
-		count = 0;
-		head = &uhci->complete_list;
-		tmp = head->next;
-		while (tmp != head) {
-			struct urb_priv *urbp = list_entry(tmp, struct urb_priv, urb_list);
-
-			out += sprintf(out, "  %d: ", ++count);
-			out += uhci_show_urbp(uhci, urbp, out, len - (out - buf));
-			tmp = tmp->next;
-		}
-	}
-
-	return out - buf;
-}
-
 static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
 {
-	unsigned long flags;
 	char *out = buf;
 	int i, j;
 	struct uhci_qh *qh;
 	struct uhci_td *td;
 	struct list_head *tmp, *head;
 
-	spin_lock_irqsave(&uhci->lock, flags);
-
 	out += uhci_show_root_hub_state(uhci, out, len - (out - buf));
 	out += sprintf(out, "HC status\n");
 	out += uhci_show_status(uhci, out, len - (out - buf));
+	if (debug <= 1)
+		return out - buf;
 
 	out += sprintf(out, "Frame List\n");
 	for (i = 0; i < UHCI_NUMFRAMES; ++i) {
-		int shown = 0;
 		td = uhci->frame_cpu[i];
 		if (!td)
 			continue;
 
-		if (td->dma_handle != (dma_addr_t)uhci->frame[i]) {
-			show_frame_num();
+		out += sprintf(out, "- Frame %d\n", i); \
+		if (td->dma_handle != (dma_addr_t)uhci->frame[i])
 			out += sprintf(out, "    frame list does not match td->dma_handle!\n");
-		}
-		show_frame_num();
 
 		head = &td->fl_list;
 		tmp = head;
@@ -467,14 +348,11 @@ static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
 	out += sprintf(out, "Skeleton QHs\n");
 
 	for (i = 0; i < UHCI_NUM_SKELQH; ++i) {
-		int shown = 0;
+		int cnt = 0;
 
 		qh = uhci->skelqh[i];
-
-		if (debug > 1) {
-			show_qh_name();
-			out += uhci_show_qh(qh, out, len - (out - buf), 4);
-		}
+		out += sprintf(out, "- %s\n", qh_names[i]); \
+		out += uhci_show_qh(qh, out, len - (out - buf), 4);
 
 		/* Last QH is the Terminating QH, it's different */
 		if (i == UHCI_NUM_SKELQH - 1) {
@@ -487,44 +365,27 @@ static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
 			continue;
 		}
 
-		j = (i < 7) ? 7 : i+1;		/* Next skeleton */
-		if (list_empty(&qh->list)) {
-			if (i < UHCI_NUM_SKELQH - 1) {
-				if (qh->link !=
-				    (cpu_to_le32(uhci->skelqh[j]->dma_handle) | UHCI_PTR_QH)) {
-					show_qh_name();
-					out += sprintf(out, "    skeleton QH not linked to next skeleton QH!\n");
-				}
-			}
-
-			continue;
-		}
-
-		show_qh_name();
-
-		head = &qh->list;
+		j = (i < 9) ? 9 : i+1;		/* Next skeleton */
+		head = &qh->node;
 		tmp = head->next;
 
 		while (tmp != head) {
-			qh = list_entry(tmp, struct uhci_qh, list);
-
+			qh = list_entry(tmp, struct uhci_qh, node);
 			tmp = tmp->next;
-
-			out += uhci_show_qh(qh, out, len - (out - buf), 4);
+			if (++cnt <= 10)
+				out += uhci_show_qh(qh, out,
+						len - (out - buf), 4);
 		}
+		if ((cnt -= 10) > 0)
+			out += sprintf(out, "    Skipped %d QHs\n", cnt);
 
-		if (i < UHCI_NUM_SKELQH - 1) {
+		if (i > 1 && i < UHCI_NUM_SKELQH - 1) {
 			if (qh->link !=
 			    (cpu_to_le32(uhci->skelqh[j]->dma_handle) | UHCI_PTR_QH))
 				out += sprintf(out, "    last QH not linked to next skeleton!\n");
 		}
 	}
 
-	if (debug > 2)
-		out += uhci_show_lists(uhci, out, len - (out - buf));
-
-	spin_unlock_irqrestore(&uhci->lock, flags);
-
 	return out - buf;
 }
 
@@ -541,6 +402,7 @@ static int uhci_debug_open(struct inode *inode, struct file *file)
 	struct uhci_hcd *uhci = inode->u.generic_ip;
 	struct uhci_debug *up;
 	int ret = -ENOMEM;
+	unsigned long flags;
 
 	lock_kernel();
 	up = kmalloc(sizeof(*up), GFP_KERNEL);
@@ -553,7 +415,9 @@ static int uhci_debug_open(struct inode *inode, struct file *file)
 		goto out;
 	}
 
+	spin_lock_irqsave(&uhci->lock, flags);
 	up->size = uhci_sprint_schedule(uhci, up->data, MAX_OUTPUT);
+	spin_unlock_irqrestore(&uhci->lock, flags);
 
 	file->private_data = up;
 
-- 
cgit v1.2.3-70-g09d2


From af0bb5998abe8ed28ee354dd4c71689cacdc91e9 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Sat, 17 Dec 2005 18:00:12 -0500
Subject: [PATCH] UHCI: use dummy TDs

This patch (as624) fixes a hardware race in uhci-hcd by adding a dummy
TD to the end of each endpoint's queue.  Without the dummy the host
controller will effectively turn off the queue when it reaches the end,
which happens asynchronously.  This leads to a potential problem when
new transfer descriptors are added to the end of the queue; they may
never get used.

With a dummy TD present the controller never turns off the queue;
instead it just stops at the dummy and leaves the queue on but inactive.
When new TDs are added to the end of the queue, the first new one gets
written over the dummy.  Thus there's never any question about whether
the queue is running or needs to be restarted.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/usb/host/uhci-debug.c |   5 ++
 drivers/usb/host/uhci-hcd.h   |   1 +
 drivers/usb/host/uhci-q.c     | 138 +++++++++++++++++++++++-------------------
 3 files changed, 83 insertions(+), 61 deletions(-)

(limited to 'drivers/usb/host/uhci-debug.c')

diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c
index 3faccbd6854..6814783adf9 100644
--- a/drivers/usb/host/uhci-debug.c
+++ b/drivers/usb/host/uhci-debug.c
@@ -189,6 +189,11 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
 					space, "", nurbs);
 	}
 
+	if (qh->udev) {
+		out += sprintf(out, "%*s  Dummy TD\n", space, "");
+		out += uhci_show_td(qh->dummy_td, out, len - (out - buf), 0);
+	}
+
 	return out - buf;
 }
 
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index 7a9481c09a0..c057956667b 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -128,6 +128,7 @@ struct uhci_qh {
 	struct usb_device *udev;
 	struct list_head queue;		/* Queue of urbps for this QH */
 	struct uhci_qh *skel;		/* Skeleton for this QH */
+	struct uhci_td *dummy_td;	/* Dummy TD to end the queue */
 
 	unsigned int unlink_frame;	/* When the QH was unlinked */
 	int state;			/* QH_STATE_xxx; see above */
diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index b1b551a3d14..c4194182dcc 100644
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -48,10 +48,6 @@ static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci)
 		return NULL;
 
 	td->dma_handle = dma_handle;
-
-	td->link = UHCI_PTR_TERM;
-	td->buffer = 0;
-
 	td->frame = -1;
 
 	INIT_LIST_HEAD(&td->list);
@@ -221,6 +217,11 @@ static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
 	INIT_LIST_HEAD(&qh->node);
 
 	if (udev) {		/* Normal QH */
+		qh->dummy_td = uhci_alloc_td(uhci);
+		if (!qh->dummy_td) {
+			dma_pool_free(uhci->qh_pool, qh, dma_handle);
+			return NULL;
+		}
 		qh->state = QH_STATE_IDLE;
 		qh->hep = hep;
 		qh->udev = udev;
@@ -244,6 +245,7 @@ static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 	if (qh->udev) {
 		qh->hep->hcpriv = NULL;
 		usb_put_dev(qh->udev);
+		uhci_free_td(uhci, qh->dummy_td);
 	}
 	dma_pool_free(uhci->qh_pool, qh, qh->dma_handle);
 }
@@ -531,22 +533,20 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
 	/* The "pipe" thing contains the destination in bits 8--18 */
 	destination = (urb->pipe & PIPE_DEVEP_MASK) | USB_PID_SETUP;
 
-	/* 3 errors */
-	status = TD_CTRL_ACTIVE | uhci_maxerr(3);
+	/* 3 errors, dummy TD remains inactive */
+	status = uhci_maxerr(3);
 	if (urb->dev->speed == USB_SPEED_LOW)
 		status |= TD_CTRL_LS;
 
 	/*
 	 * Build the TD for the control request setup packet
 	 */
-	td = uhci_alloc_td(uhci);
-	if (!td)
-		return -ENOMEM;
-
+	td = qh->dummy_td;
 	uhci_add_td_to_urb(urb, td);
 	uhci_fill_td(td, status, destination | uhci_explen(8),
 			urb->setup_dma);
 	plink = &td->link;
+	status |= TD_CTRL_ACTIVE;
 
 	/*
 	 * If direction is "send", change the packet ID from SETUP (0x2D)
@@ -568,7 +568,7 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
 
 		td = uhci_alloc_td(uhci);
 		if (!td)
-			return -ENOMEM;
+			goto nomem;
 		*plink = cpu_to_le32(td->dma_handle);
 
 		/* Alternate Data0/1 (start with Data1) */
@@ -588,7 +588,7 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
 	 */
 	td = uhci_alloc_td(uhci);
 	if (!td)
-		return -ENOMEM;
+		goto nomem;
 	*plink = cpu_to_le32(td->dma_handle);
 
 	/*
@@ -608,6 +608,20 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
 	uhci_add_td_to_urb(urb, td);
 	uhci_fill_td(td, status | TD_CTRL_IOC,
 			destination | uhci_explen(0), 0);
+	plink = &td->link;
+
+	/*
+	 * Build the new dummy TD and activate the old one
+	 */
+	td = uhci_alloc_td(uhci);
+	if (!td)
+		goto nomem;
+	*plink = cpu_to_le32(td->dma_handle);
+
+	uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
+	wmb();
+	qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);
+	qh->dummy_td = td;
 
 	/* Low-speed transfers get a different queue, and won't hog the bus.
 	 * Also, some devices enumerate better without FSBR; the easiest way
@@ -620,8 +634,12 @@ static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
 		qh->skel = uhci->skel_fs_control_qh;
 		uhci_inc_fsbr(uhci, urb);
 	}
-
 	return 0;
+
+nomem:
+	/* Remove the dummy TD from the td_list so it doesn't get freed */
+	uhci_remove_td_from_urb(qh->dummy_td);
+	return -ENOMEM;
 }
 
 /*
@@ -761,16 +779,19 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
 	int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
 	int len = urb->transfer_buffer_length;
 	dma_addr_t data = urb->transfer_dma;
-	__le32 *plink, fake_link;
+	__le32 *plink;
+	unsigned int toggle;
 
 	if (len < 0)
 		return -EINVAL;
 
 	/* The "pipe" thing contains the destination in bits 8--18 */
 	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
+	toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+			 usb_pipeout(urb->pipe));
 
-	/* 3 errors */
-	status = TD_CTRL_ACTIVE | uhci_maxerr(3);
+	/* 3 errors, dummy TD remains inactive */
+	status = uhci_maxerr(3);
 	if (urb->dev->speed == USB_SPEED_LOW)
 		status |= TD_CTRL_LS;
 	if (usb_pipein(urb->pipe))
@@ -779,7 +800,8 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
 	/*
 	 * Build the DATA TDs
 	 */
-	plink = &fake_link;
+	plink = NULL;
+	td = qh->dummy_td;
 	do {	/* Allow zero length packets */
 		int pktsze = maxsze;
 
@@ -789,24 +811,23 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
 				status &= ~TD_CTRL_SPD;
 		}
 
-		td = uhci_alloc_td(uhci);
-		if (!td)
-			return -ENOMEM;
-		*plink = cpu_to_le32(td->dma_handle);
-
+		if (plink) {
+			td = uhci_alloc_td(uhci);
+			if (!td)
+				goto nomem;
+			*plink = cpu_to_le32(td->dma_handle);
+		}
 		uhci_add_td_to_urb(urb, td);
 		uhci_fill_td(td, status,
-			destination | uhci_explen(pktsze) |
-			(usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
-			 usb_pipeout(urb->pipe)) << TD_TOKEN_TOGGLE_SHIFT),
-			data);
+				destination | uhci_explen(pktsze) |
+					(toggle << TD_TOKEN_TOGGLE_SHIFT),
+				data);
 		plink = &td->link;
+		status |= TD_CTRL_ACTIVE;
 
 		data += pktsze;
 		len -= maxsze;
-
-		usb_dotoggle(urb->dev, usb_pipeendpoint(urb->pipe),
-			usb_pipeout(urb->pipe));
+		toggle ^= 1;
 	} while (len > 0);
 
 	/*
@@ -821,17 +842,17 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
 			urb->transfer_buffer_length > 0) {
 		td = uhci_alloc_td(uhci);
 		if (!td)
-			return -ENOMEM;
+			goto nomem;
 		*plink = cpu_to_le32(td->dma_handle);
 
 		uhci_add_td_to_urb(urb, td);
-		uhci_fill_td(td, status, destination | uhci_explen(0) |
-			(usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
-			 usb_pipeout(urb->pipe)) << TD_TOKEN_TOGGLE_SHIFT),
-			data);
+		uhci_fill_td(td, status,
+				destination | uhci_explen(0) |
+					(toggle << TD_TOKEN_TOGGLE_SHIFT),
+				data);
+		plink = &td->link;
 
-		usb_dotoggle(urb->dev, usb_pipeendpoint(urb->pipe),
-			usb_pipeout(urb->pipe));
+		toggle ^= 1;
 	}
 
 	/* Set the interrupt-on-completion flag on the last packet.
@@ -842,7 +863,27 @@ static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
 	 * flag setting. */
 	td->status |= __constant_cpu_to_le32(TD_CTRL_IOC);
 
+	/*
+	 * Build the new dummy TD and activate the old one
+	 */
+	td = uhci_alloc_td(uhci);
+	if (!td)
+		goto nomem;
+	*plink = cpu_to_le32(td->dma_handle);
+
+	uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
+	wmb();
+	qh->dummy_td->status |= __constant_cpu_to_le32(TD_CTRL_ACTIVE);
+	qh->dummy_td = td;
+
+	usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+			usb_pipeout(urb->pipe), toggle);
 	return 0;
+
+nomem:
+	/* Remove the dummy TD from the td_list so it doesn't get freed */
+	uhci_remove_td_from_urb(qh->dummy_td);
+	return -ENOMEM;
 }
 
 /*
@@ -1169,31 +1210,6 @@ static int uhci_urb_enqueue(struct usb_hcd *hcd,
 	 * become idle, so we can activate it right away. */
 	if (qh->queue.next == &urbp->node)
 		uhci_activate_qh(uhci, qh);
-
-	/* If the QH is already active, we have a race with the hardware.
-	 * This won't get fixed until dummy TDs are added. */
-	else if (qh->state == QH_STATE_ACTIVE) {
-
-		/* If the URB isn't first on its queue, adjust the link pointer
-		 * of the last TD in the previous URB. */
-		if (urbp->node.prev != &urbp->qh->queue) {
-			struct urb_priv *purbp = list_entry(urbp->node.prev,
-					struct urb_priv, node);
-			struct uhci_td *ptd = list_entry(purbp->td_list.prev,
-					struct uhci_td, list);
-			struct uhci_td *td = list_entry(urbp->td_list.next,
-					struct uhci_td, list);
-
-			ptd->link = cpu_to_le32(td->dma_handle);
-
-		}
-		if (qh_element(qh) == UHCI_PTR_TERM) {
-			struct uhci_td *td = list_entry(urbp->td_list.next,
-					struct uhci_td, list);
-
-			qh->element = cpu_to_le32(td->dma_handle);
-		}
-	}
 	goto done;
 
 err_submit_failed:
-- 
cgit v1.2.3-70-g09d2


From 0ed8fee1c1d38a62e981025ba40b5eba30c4ce2a Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Sat, 17 Dec 2005 18:02:38 -0500
Subject: [PATCH] UHCI: remove main list of URBs

As part of reorienting uhci-hcd away from URBs and toward endpoint
queues, this patch (as625) eliminates the driver's main list of URBs.
The list wsa used mainly in checking for URB completions; now the driver
goes through the list of active endpoints and checks the members of the
queues.

As a side effect, I had to remove the code that looks for FSBR timeouts.
For now, FSBR will remain on so long as any URBs on a full-speed control
or bulk queue request it, even if the queue isn't advancing.  A later
patch can add more intelligent handling.  This isn't a huge drawback;
it's pretty rare for an URB to get stuck for more than a fraction of a
second.  (And it will help the people trying to use those insane HP USB
devices.)

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/usb/host/uhci-debug.c |   1 -
 drivers/usb/host/uhci-hcd.c   |   2 -
 drivers/usb/host/uhci-hcd.h   |  15 +-
 drivers/usb/host/uhci-q.c     | 631 ++++++++++++++++++------------------------
 4 files changed, 279 insertions(+), 370 deletions(-)

(limited to 'drivers/usb/host/uhci-debug.c')

diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c
index 6814783adf9..f2f5f8ce171 100644
--- a/drivers/usb/host/uhci-debug.c
+++ b/drivers/usb/host/uhci-debug.c
@@ -114,7 +114,6 @@ static int uhci_show_urbp(struct urb_priv *urbp, char *buf, int len, int space)
 	}
 
 	out += sprintf(out, "%s", (urbp->fsbr ? " FSBR" : ""));
-	out += sprintf(out, "%s", (urbp->fsbr_timeout ? " FSBR_TO" : ""));
 
 	if (urbp->urb->status != -EINPROGRESS)
 		out += sprintf(out, " Status=%d", urbp->urb->status);
diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 1ff4b880637..9865f303d3f 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -491,8 +491,6 @@ static int uhci_start(struct usb_hcd *hcd)
 	spin_lock_init(&uhci->lock);
 
 	INIT_LIST_HEAD(&uhci->td_remove_list);
-	INIT_LIST_HEAD(&uhci->urb_list);
-	INIT_LIST_HEAD(&uhci->complete_list);
 	INIT_LIST_HEAD(&uhci->idle_qh_list);
 
 	init_waitqueue_head(&uhci->waitqh);
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index c057956667b..7e96bef2e88 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -132,6 +132,10 @@ struct uhci_qh {
 
 	unsigned int unlink_frame;	/* When the QH was unlinked */
 	int state;			/* QH_STATE_xxx; see above */
+
+	unsigned int initial_toggle:1;	/* Endpoint's current toggle value */
+	unsigned int needs_fixup:1;	/* Must fix the TD toggle values */
+	unsigned int is_stopped:1;	/* Queue was stopped by an error */
 } __attribute__((aligned(16)));
 
 /*
@@ -384,6 +388,7 @@ struct uhci_hcd {
 
 	struct uhci_td *term_td;	/* Terminating TD, see UHCI bug */
 	struct uhci_qh *skelqh[UHCI_NUM_SKELQH];	/* Skeleton QHs */
+	struct uhci_qh *next_qh;	/* Next QH to scan */
 
 	spinlock_t lock;
 
@@ -413,16 +418,10 @@ struct uhci_hcd {
 	unsigned long resuming_ports;
 	unsigned long ports_timeout;		/* Time to stop signalling */
 
-	/* Main list of URBs currently controlled by this HC */
-	struct list_head urb_list;
-
 	/* List of TDs that are done, but waiting to be freed (race) */
 	struct list_head td_remove_list;
 	unsigned int td_remove_age;		/* Age in frames */
 
-	/* List of URBs awaiting completion callback */
-	struct list_head complete_list;
-
 	struct list_head idle_qh_list;		/* Where the idle QHs live */
 
 	int rh_numports;			/* Number of root-hub ports */
@@ -448,7 +447,6 @@ static inline struct usb_hcd *uhci_to_hcd(struct uhci_hcd *uhci)
  *	Private per-URB data
  */
 struct urb_priv {
-	struct list_head urb_list;
 	struct list_head node;		/* Node in the QH's urbp list */
 
 	struct urb *urb;
@@ -456,10 +454,7 @@ struct urb_priv {
 	struct uhci_qh *qh;		/* QH for this URB */
 	struct list_head td_list;
 
-	unsigned long fsbrtime;		/* In jiffies */
-
 	unsigned fsbr : 1;		/* URB turned on FSBR */
-	unsigned fsbr_timeout : 1;	/* URB timed out on FSBR */
 	unsigned short_transfer : 1;	/* URB got a short transfer, no
 					 * need to rescan */
 };
diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index c4194182dcc..44bba9a6d19 100644
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -151,53 +151,6 @@ static void uhci_unlink_isochronous_tds(struct uhci_hcd *uhci, struct urb *urb)
 	wmb();
 }
 
-/*
- * Remove an URB's TDs from the hardware schedule
- */
-static void uhci_remove_tds_from_schedule(struct uhci_hcd *uhci,
-		struct urb *urb, int status)
-{
-	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
-
-	/* Isochronous TDs get unlinked directly from the frame list */
-	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
-		uhci_unlink_isochronous_tds(uhci, urb);
-		return;
-	}
-
-	/* If the URB isn't first on its queue, adjust the link pointer
-	 * of the last TD in the previous URB. */
-	if (urbp->node.prev != &urbp->qh->queue) {
-		struct urb_priv *purbp;
-		struct uhci_td *ptd, *ltd;
-
-		if (status == -EINPROGRESS)
-			status = 0;
-		purbp = list_entry(urbp->node.prev, struct urb_priv, node);
-		ptd = list_entry(purbp->td_list.prev, struct uhci_td,
-				list);
-		ltd = list_entry(urbp->td_list.prev, struct uhci_td,
-				list);
-		ptd->link = ltd->link;
-	}
-
-	/* If the URB completed with an error, then the QH element certainly
-	 * points to one of the URB's TDs.  If it completed normally then
-	 * the QH element has certainly moved on to the next URB.  And if
-	 * the URB is still in progress then it must have been dequeued.
-	 * The QH element either hasn't reached it yet or is somewhere in
-	 * the middle.  If the URB wasn't first we can assume that it
-	 * hasn't started yet (see above): Otherwise all the preceding URBs
-	 * would have completed and been removed from the queue, so this one
-	 * _would_ be first.
-	 *
-	 * If the QH element is inside this URB, clear it.  It will be
-	 * set properly when the QH is activated.
-	 */
-	if (status < 0)
-		urbp->qh->element = UHCI_PTR_TERM;
-}
-
 static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
 		struct usb_device *udev, struct usb_host_endpoint *hep)
 {
@@ -250,6 +203,90 @@ static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 	dma_pool_free(uhci->qh_pool, qh, qh->dma_handle);
 }
 
+/*
+ * When the currently executing URB is dequeued, save its current toggle value
+ */
+static void uhci_save_toggle(struct uhci_qh *qh, struct urb *urb)
+{
+	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
+	struct uhci_td *td;
+
+	/* If the QH element pointer is UHCI_PTR_TERM then then currently
+	 * executing URB has already been unlinked, so this one isn't it. */
+	if (qh_element(qh) == UHCI_PTR_TERM ||
+				qh->queue.next != &urbp->node)
+		return;
+	qh->element = UHCI_PTR_TERM;
+
+	/* Only bulk and interrupt pipes have to worry about toggles */
+	if (!(usb_pipetype(urb->pipe) == PIPE_BULK ||
+			usb_pipetype(urb->pipe) == PIPE_INTERRUPT))
+		return;
+
+	/* Find the first active TD; that's the device's toggle state */
+	list_for_each_entry(td, &urbp->td_list, list) {
+		if (td_status(td) & TD_CTRL_ACTIVE) {
+			qh->needs_fixup = 1;
+			qh->initial_toggle = uhci_toggle(td_token(td));
+			return;
+		}
+	}
+
+	WARN_ON(1);
+}
+
+/*
+ * Fix up the data toggles for URBs in a queue, when one of them
+ * terminates early (short transfer, error, or dequeued).
+ */
+static void uhci_fixup_toggles(struct uhci_qh *qh, int skip_first)
+{
+	struct urb_priv *urbp = NULL;
+	struct uhci_td *td;
+	unsigned int toggle = qh->initial_toggle;
+	unsigned int pipe;
+
+	/* Fixups for a short transfer start with the second URB in the
+	 * queue (the short URB is the first). */
+	if (skip_first)
+		urbp = list_entry(qh->queue.next, struct urb_priv, node);
+
+	/* When starting with the first URB, if the QH element pointer is
+	 * still valid then we know the URB's toggles are okay. */
+	else if (qh_element(qh) != UHCI_PTR_TERM)
+		toggle = 2;
+
+	/* Fix up the toggle for the URBs in the queue.  Normally this
+	 * loop won't run more than once: When an error or short transfer
+	 * occurs, the queue usually gets emptied. */
+	list_prepare_entry(urbp, &qh->queue, node);
+	list_for_each_entry_continue(urbp, &qh->queue, node) {
+
+		/* If the first TD has the right toggle value, we don't
+		 * need to change any toggles in this URB */
+		td = list_entry(urbp->td_list.next, struct uhci_td, list);
+		if (toggle > 1 || uhci_toggle(td_token(td)) == toggle) {
+			td = list_entry(urbp->td_list.next, struct uhci_td,
+					list);
+			toggle = uhci_toggle(td_token(td)) ^ 1;
+
+		/* Otherwise all the toggles in the URB have to be switched */
+		} else {
+			list_for_each_entry(td, &urbp->td_list, list) {
+				td->token ^= __constant_cpu_to_le32(
+							TD_TOKEN_TOGGLE);
+				toggle ^= 1;
+			}
+		}
+	}
+
+	wmb();
+	pipe = list_entry(qh->queue.next, struct urb_priv, node)->urb->pipe;
+	usb_settoggle(qh->udev, usb_pipeendpoint(pipe),
+			usb_pipeout(pipe), toggle);
+	qh->needs_fixup = 0;
+}
+
 /*
  * Put a QH on the schedule in both hardware and software
  */
@@ -276,6 +313,9 @@ static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 
 	/* Move the QH from its old list to the end of the appropriate
 	 * skeleton's list */
+	if (qh == uhci->next_qh)
+		uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
+				node);
 	list_move_tail(&qh->node, &qh->skel->node);
 
 	/* Link it into the schedule */
@@ -310,6 +350,9 @@ static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 		uhci_set_next_interrupt(uhci);
 
 	/* Move the QH from its old list to the end of the unlinking list */
+	if (qh == uhci->next_qh)
+		uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
+				node);
 	list_move_tail(&qh->node, &uhci->skel_unlink_qh->node);
 }
 
@@ -323,6 +366,9 @@ static void uhci_make_qh_idle(struct uhci_hcd *uhci, struct uhci_qh *qh)
 {
 	WARN_ON(qh->state == QH_STATE_ACTIVE);
 
+	if (qh == uhci->next_qh)
+		uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
+				node);
 	list_move(&qh->node, &uhci->idle_qh_list);
 	qh->state = QH_STATE_IDLE;
 
@@ -344,11 +390,9 @@ static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci,
 
 	urbp->urb = urb;
 	urb->hcpriv = urbp;
-	urbp->fsbrtime = jiffies;
 	
 	INIT_LIST_HEAD(&urbp->node);
 	INIT_LIST_HEAD(&urbp->td_list);
-	INIT_LIST_HEAD(&urbp->urb_list);
 
 	return urbp;
 }
@@ -373,9 +417,6 @@ static void uhci_free_urb_priv(struct uhci_hcd *uhci,
 {
 	struct uhci_td *td, *tmp;
 
-	if (!list_empty(&urbp->urb_list))
-		dev_warn(uhci_dev(uhci), "urb %p still on uhci->urb_list!\n",
-				urbp->urb);
 	if (!list_empty(&urbp->node))
 		dev_warn(uhci_dev(uhci), "urb %p still on QH's list!\n",
 				urbp->urb);
@@ -452,71 +493,6 @@ static int uhci_map_status(int status, int dir_out)
 	return 0;
 }
 
-/*
- * Fix up the data toggles for URBs in a queue, when one of them
- * terminates early (short transfer, error, or dequeued).
- */
-static void uhci_fixup_toggles(struct urb *urb)
-{
-	struct list_head *head;
-	struct uhci_td *td;
-	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
-	int prevactive = 0;
-	unsigned int toggle = 0;
-	struct urb_priv *turbp, *list_end;
-
-	/*
-	 * We need to find out what the last successful toggle was so
-	 * we can update the data toggles for the following transfers.
-	 *
-	 * There are 2 ways the last successful completed TD is found:
-	 *
-	 * 1) The TD is NOT active and the actual length < expected length
-	 * 2) The TD is NOT active and it's the last TD in the chain
-	 *
-	 * and a third way the first uncompleted TD is found:
-	 *
-	 * 3) The TD is active and the previous TD is NOT active
-	 */
-	head = &urbp->td_list;
-	list_for_each_entry(td, head, list) {
-		unsigned int ctrlstat = td_status(td);
-
-		if (!(ctrlstat & TD_CTRL_ACTIVE) &&
-				(uhci_actual_length(ctrlstat) <
-				 uhci_expected_length(td_token(td)) ||
-				td->list.next == head))
-			toggle = uhci_toggle(td_token(td)) ^ 1;
-		else if ((ctrlstat & TD_CTRL_ACTIVE) && !prevactive)
-			toggle = uhci_toggle(td_token(td));
-
-		prevactive = ctrlstat & TD_CTRL_ACTIVE;
-	}
-
-	/*
-	 * Fix up the toggle for the following URBs in the queue.
-	 *
-	 * We can stop as soon as we find an URB with toggles set correctly,
-	 * because then all the following URBs will be correct also.
-	 */
-	list_end = list_entry(&urbp->qh->queue, struct urb_priv, node);
-	turbp = urbp;
-	while ((turbp = list_entry(turbp->node.next, struct urb_priv, node))
-			!= list_end) {
-		td = list_entry(turbp->td_list.next, struct uhci_td, list);
-		if (uhci_toggle(td_token(td)) == toggle)
-			return;
-
-		list_for_each_entry(td, &turbp->td_list, list) {
-			td->token ^= __constant_cpu_to_le32(TD_TOKEN_TOGGLE);
-			toggle ^= 1;
-		}
-	}
-
-	usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
-			usb_pipeout(urb->pipe), toggle);
-}
-
 /*
  * Control transfers
  */
@@ -765,6 +741,9 @@ err:
 		}
 	}
 
+	/* Note that the queue has stopped */
+	urbp->qh->element = UHCI_PTR_TERM;
+	urbp->qh->is_stopped = 1;
 	return ret;
 }
 
@@ -927,7 +906,10 @@ static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
 			 */
 			if (!urbp->short_transfer) {
 				urbp->short_transfer = 1;
-				uhci_fixup_toggles(urb);
+				urbp->qh->initial_toggle =
+						uhci_toggle(td_token(td)) ^ 1;
+				uhci_fixup_toggles(urbp->qh, 1);
+
 				td = list_entry(urbp->td_list.prev,
 						struct uhci_td, list);
 				urbp->qh->element = td->link;
@@ -962,6 +944,13 @@ err:
 		}
 	}
 #endif
+
+	/* Note that the queue has stopped and save the next toggle value */
+	urbp->qh->element = UHCI_PTR_TERM;
+	urbp->qh->is_stopped = 1;
+	urbp->qh->needs_fixup = 1;
+	urbp->qh->initial_toggle = uhci_toggle(td_token(td)) ^
+			(ret == -EREMOTEIO);
 	return ret;
 }
 
@@ -995,76 +984,39 @@ static inline int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,
 /*
  * Isochronous transfers
  */
-static int isochronous_find_limits(struct uhci_hcd *uhci, struct urb *urb, unsigned int *start, unsigned int *end)
-{
-	struct urb *last_urb = NULL;
-	struct urb_priv *up;
-	int ret = 0;
-
-	list_for_each_entry(up, &uhci->urb_list, urb_list) {
-		struct urb *u = up->urb;
-
-		/* look for pending URBs with identical pipe handle */
-		if ((urb->pipe == u->pipe) && (urb->dev == u->dev) &&
-		    (u->status == -EINPROGRESS) && (u != urb)) {
-			if (!last_urb)
-				*start = u->start_frame;
-			last_urb = u;
-		}
-	}
-
-	if (last_urb) {
-		*end = (last_urb->start_frame + last_urb->number_of_packets *
-				last_urb->interval) & (UHCI_NUMFRAMES-1);
-		ret = 0;
-	} else
-		ret = -1;	/* no previous urb found */
-
-	return ret;
-}
-
-static int isochronous_find_start(struct uhci_hcd *uhci, struct urb *urb)
+static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
+		struct uhci_qh *qh)
 {
-	int limits;
-	unsigned int start = 0, end = 0;
+	struct uhci_td *td = NULL;	/* Since urb->number_of_packets > 0 */
+	int i, frame;
+	unsigned long destination, status;
+	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 
 	if (urb->number_of_packets > 900)	/* 900? Why? */
 		return -EFBIG;
 
-	limits = isochronous_find_limits(uhci, urb, &start, &end);
+	status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
+	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
 
+	/* Figure out the starting frame number */
 	if (urb->transfer_flags & URB_ISO_ASAP) {
-		if (limits) {
+		if (list_empty(&qh->queue)) {
 			uhci_get_current_frame_number(uhci);
-			urb->start_frame = (uhci->frame_number + 10)
-					& (UHCI_NUMFRAMES - 1);
-		} else
-			urb->start_frame = end;
+			urb->start_frame = (uhci->frame_number + 10);
+
+		} else {		/* Go right after the last one */
+			struct urb *last_urb;
+
+			last_urb = list_entry(qh->queue.prev,
+					struct urb_priv, node)->urb;
+			urb->start_frame = (last_urb->start_frame +
+					last_urb->number_of_packets *
+					last_urb->interval);
+		}
 	} else {
-		urb->start_frame &= (UHCI_NUMFRAMES - 1);
 		/* FIXME: Sanity check */
 	}
-
-	return 0;
-}
-
-/*
- * Isochronous transfers
- */
-static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
-		struct uhci_qh *qh)
-{
-	struct uhci_td *td = NULL;	/* Since urb->number_of_packets > 0 */
-	int i, ret, frame;
-	unsigned long destination, status;
-	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
-
-	status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
-	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
-
-	ret = isochronous_find_start(uhci, urb);
-	if (ret)
-		return ret;
+	urb->start_frame &= (UHCI_NUMFRAMES - 1);
 
 	for (i = 0; i < urb->number_of_packets; i++) {
 		td = uhci_alloc_td(uhci);
@@ -1203,7 +1155,6 @@ static int uhci_urb_enqueue(struct usb_hcd *hcd,
 	/* Add this URB to the QH */
 	urbp->qh = qh;
 	list_add_tail(&urbp->node, &qh->queue);
-	list_add_tail(&urbp->urb_list, &uhci->urb_list);
 
 	/* If the new URB is the first and only one on this QH then either
 	 * the QH is new and idle or else it's unlinked and waiting to
@@ -1224,49 +1175,66 @@ done:
 	return ret;
 }
 
+static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb)
+{
+	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
+	unsigned long flags;
+	struct urb_priv *urbp;
+
+	spin_lock_irqsave(&uhci->lock, flags);
+	urbp = urb->hcpriv;
+	if (!urbp)			/* URB was never linked! */
+		goto done;
+
+	/* Remove Isochronous TDs from the frame list ASAP */
+	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
+		uhci_unlink_isochronous_tds(uhci, urb);
+	uhci_unlink_qh(uhci, urbp->qh);
+
+done:
+	spin_unlock_irqrestore(&uhci->lock, flags);
+	return 0;
+}
+
 /*
- * Return the result of a transfer
+ * Finish unlinking an URB and give it back
  */
-static void uhci_transfer_result(struct uhci_hcd *uhci, struct urb *urb)
+static void uhci_giveback_urb(struct uhci_hcd *uhci, struct uhci_qh *qh,
+		struct urb *urb, struct pt_regs *regs)
+__releases(uhci->lock)
+__acquires(uhci->lock)
 {
-	int status;
-	int okay_to_giveback = 0;
 	struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 
-	switch (usb_pipetype(urb->pipe)) {
-	case PIPE_CONTROL:
-		status = uhci_result_control(uhci, urb);
-		break;
-	case PIPE_ISOCHRONOUS:
-		status = uhci_result_isochronous(uhci, urb);
-		break;
-	default:	/* PIPE_BULK or PIPE_INTERRUPT */
-		status = uhci_result_common(uhci, urb);
-		break;
-	}
+	/* Isochronous TDs get unlinked directly from the frame list */
+	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
+		uhci_unlink_isochronous_tds(uhci, urb);
 
-	spin_lock(&urb->lock);
-	if (urb->status == -EINPROGRESS) {	/* Not yet dequeued */
-		if (status != -EINPROGRESS) {	/* URB has completed */
-			urb->status = status;
+	/* If the URB isn't first on its queue, adjust the link pointer
+	 * of the last TD in the previous URB. */
+	else if (qh->queue.next != &urbp->node) {
+		struct urb_priv *purbp;
+		struct uhci_td *ptd, *ltd;
 
-			/* If the URB got a real error (as opposed to
-			 * simply being dequeued), we don't have to
-			 * unlink the QH.  Fix this later... */
-			if (status < 0)
-				uhci_unlink_qh(uhci, urbp->qh);
-			else
-				okay_to_giveback = 1;
-		}
-	} else {				/* Already dequeued */
-		if (urbp->qh->state == QH_STATE_UNLINKING &&
-				uhci->frame_number + uhci->is_stopped !=
-				urbp->qh->unlink_frame)
-			okay_to_giveback = 1;
+		purbp = list_entry(urbp->node.prev, struct urb_priv, node);
+		ptd = list_entry(purbp->td_list.prev, struct uhci_td,
+				list);
+		ltd = list_entry(urbp->td_list.prev, struct uhci_td,
+				list);
+		ptd->link = ltd->link;
 	}
-	spin_unlock(&urb->lock);
-	if (!okay_to_giveback)
-		return;
+
+	/* Take the URB off the QH's queue.  If the queue is now empty,
+	 * this is a perfect time for a toggle fixup. */
+	list_del_init(&urbp->node);
+	if (list_empty(&qh->queue) && qh->needs_fixup) {
+		usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
+				usb_pipeout(urb->pipe), qh->initial_toggle);
+		qh->needs_fixup = 0;
+	}
+
+	uhci_dec_fsbr(uhci, urb);	/* Safe since it checks */
+	uhci_free_urb_priv(uhci, urbp);
 
 	switch (usb_pipetype(urb->pipe)) {
 	case PIPE_ISOCHRONOUS:
@@ -1277,122 +1245,107 @@ static void uhci_transfer_result(struct uhci_hcd *uhci, struct urb *urb)
 	case PIPE_INTERRUPT:
 		/* Release bandwidth for Interrupt or Isoc. transfers */
 		/* Make sure we don't release if we have a queued URB */
-		if (list_empty(&urbp->qh->queue) && urb->bandwidth)
+		if (list_empty(&qh->queue) && urb->bandwidth)
 			usb_release_bandwidth(urb->dev, urb, 0);
 		else
 			/* bandwidth was passed on to queued URB, */
 			/* so don't let usb_unlink_urb() release it */
 			urb->bandwidth = 0;
-		/* Falls through */
-	case PIPE_BULK:
-		if (status < 0)
-			uhci_fixup_toggles(urb);
-		break;
-	default:	/* PIPE_CONTROL */
 		break;
 	}
 
-	/* Take the URB's TDs off the hardware schedule */
-	uhci_remove_tds_from_schedule(uhci, urb, status);
-
-	/* Take the URB off the QH's queue and see if the QH is now unused */
-	list_del_init(&urbp->node);
-	if (list_empty(&urbp->qh->queue))
-		uhci_unlink_qh(uhci, urbp->qh);
+	spin_unlock(&uhci->lock);
+	usb_hcd_giveback_urb(uhci_to_hcd(uhci), urb, regs);
+	spin_lock(&uhci->lock);
 
-	uhci_dec_fsbr(uhci, urb);	/* Safe since it checks */
+	/* If the queue is now empty, we can unlink the QH and give up its
+	 * reserved bandwidth. */
+	if (list_empty(&qh->queue)) {
+		uhci_unlink_qh(uhci, qh);
 
-	/* Queue it for giving back */
-	list_move_tail(&urbp->urb_list, &uhci->complete_list);
+		/* Bandwidth stuff not yet implemented */
+	}
 }
 
 /*
- * Check out the QHs waiting to be fully unlinked
+ * Scan the URBs in a QH's queue
  */
-static void uhci_scan_unlinking_qhs(struct uhci_hcd *uhci)
-{
-	struct uhci_qh *qh, *tmp;
+#define QH_FINISHED_UNLINKING(qh)			\
+		(qh->state == QH_STATE_UNLINKING &&	\
+		uhci->frame_number + uhci->is_stopped != qh->unlink_frame)
 
-	list_for_each_entry_safe(qh, tmp, &uhci->skel_unlink_qh->node, node) {
-
-		/* If the queue is empty and the QH is fully unlinked then
-		 * it can become IDLE. */
-		if (list_empty(&qh->queue)) {
-			if (uhci->frame_number + uhci->is_stopped !=
-					qh->unlink_frame)
-				uhci_make_qh_idle(uhci, qh);
-
-		/* If none of the QH's URBs have been dequeued then the QH
-		 * should be re-activated. */
-		} else {
-			struct urb_priv *urbp;
-			int any_dequeued = 0;
-
-			list_for_each_entry(urbp, &qh->queue, node) {
-				if (urbp->urb->status != -EINPROGRESS) {
-					any_dequeued = 1;
-					break;
-				}
-			}
-			if (!any_dequeued)
-				uhci_activate_qh(uhci, qh);
-		}
-	}
-}
-
-static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb)
+static void uhci_scan_qh(struct uhci_hcd *uhci, struct uhci_qh *qh,
+		struct pt_regs *regs)
 {
-	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
-	unsigned long flags;
 	struct urb_priv *urbp;
+	struct urb *urb;
+	int status;
 
-	spin_lock_irqsave(&uhci->lock, flags);
-	urbp = urb->hcpriv;
-	if (!urbp)			/* URB was never linked! */
-		goto done;
+	while (!list_empty(&qh->queue)) {
+		urbp = list_entry(qh->queue.next, struct urb_priv, node);
+		urb = urbp->urb;
 
-	/* Remove Isochronous TDs from the frame list ASAP */
-	if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
-		uhci_unlink_isochronous_tds(uhci, urb);
-	uhci_unlink_qh(uhci, urbp->qh);
+		switch (usb_pipetype(urb->pipe)) {
+		case PIPE_CONTROL:
+			status = uhci_result_control(uhci, urb);
+			break;
+		case PIPE_ISOCHRONOUS:
+			status = uhci_result_isochronous(uhci, urb);
+			break;
+		default:	/* PIPE_BULK or PIPE_INTERRUPT */
+			status = uhci_result_common(uhci, urb);
+			break;
+		}
+		if (status == -EINPROGRESS)
+			break;
 
-done:
-	spin_unlock_irqrestore(&uhci->lock, flags);
-	return 0;
-}
+		spin_lock(&urb->lock);
+		if (urb->status == -EINPROGRESS)	/* Not dequeued */
+			urb->status = status;
+		else
+			status = -ECONNRESET;
+		spin_unlock(&urb->lock);
 
-static int uhci_fsbr_timeout(struct uhci_hcd *uhci, struct urb *urb)
-{
-	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
-	struct list_head *head;
-	struct uhci_td *td;
-	int count = 0;
+		/* Dequeued but completed URBs can't be given back unless
+		 * the QH is stopped or has finished unlinking. */
+		if (status == -ECONNRESET &&
+				!(qh->is_stopped || QH_FINISHED_UNLINKING(qh)))
+			return;
 
-	uhci_dec_fsbr(uhci, urb);
+		uhci_giveback_urb(uhci, qh, urb, regs);
+		if (qh->is_stopped)
+			break;
+	}
 
-	urbp->fsbr_timeout = 1;
+	/* If the QH is neither stopped nor finished unlinking (normal case),
+	 * our work here is done. */
+ restart:
+	if (!(qh->is_stopped || QH_FINISHED_UNLINKING(qh)))
+		return;
 
-	/*
-	 * Ideally we would want to fix qh->element as well, but it's
-	 * read/write by the HC, so that can introduce a race. It's not
-	 * really worth the hassle
-	 */
+	/* Otherwise give back each of the dequeued URBs */
+	list_for_each_entry(urbp, &qh->queue, node) {
+		urb = urbp->urb;
+		if (urb->status != -EINPROGRESS) {
+			uhci_save_toggle(qh, urb);
+			uhci_giveback_urb(uhci, qh, urb, regs);
+			goto restart;
+		}
+	}
+	qh->is_stopped = 0;
 
-	head = &urbp->td_list;
-	list_for_each_entry(td, head, list) {
-		/*
-		 * Make sure we don't do the last one (since it'll have the
-		 * TERM bit set) as well as we skip every so many TDs to
-		 * make sure it doesn't hog the bandwidth
-		 */
-		if (td->list.next != head && (count % DEPTH_INTERVAL) ==
-				(DEPTH_INTERVAL - 1))
-			td->link |= UHCI_PTR_DEPTH;
-
-		count++;
+	/* There are no more dequeued URBs.  If there are still URBs on the
+	 * queue, the QH can now be re-activated. */
+	if (!list_empty(&qh->queue)) {
+		if (qh->needs_fixup)
+			uhci_fixup_toggles(qh, 0);
+		uhci_activate_qh(uhci, qh);
 	}
 
-	return 0;
+	/* The queue is empty.  The QH can become idle if it is fully
+	 * unlinked. */
+	else if (QH_FINISHED_UNLINKING(qh))
+		uhci_make_qh_idle(uhci, qh);
 }
 
 static void uhci_free_pending_tds(struct uhci_hcd *uhci)
@@ -1406,36 +1359,13 @@ static void uhci_free_pending_tds(struct uhci_hcd *uhci)
 	}
 }
 
-static void
-uhci_finish_urb(struct usb_hcd *hcd, struct urb *urb, struct pt_regs *regs)
-__releases(uhci->lock)
-__acquires(uhci->lock)
-{
-	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
-
-	uhci_free_urb_priv(uhci, (struct urb_priv *) (urb->hcpriv));
-
-	spin_unlock(&uhci->lock);
-	usb_hcd_giveback_urb(hcd, urb, regs);
-	spin_lock(&uhci->lock);
-}
-
-static void uhci_finish_completion(struct uhci_hcd *uhci, struct pt_regs *regs)
-{
-	struct urb_priv *urbp, *tmp;
-
-	list_for_each_entry_safe(urbp, tmp, &uhci->complete_list, urb_list) {
-		struct urb *urb = urbp->urb;
-
-		list_del_init(&urbp->urb_list);
-		uhci_finish_urb(uhci_to_hcd(uhci), urb, regs);
-	}
-}
-
-/* Process events in the schedule, but only in one thread at a time */
+/*
+ * Process events in the schedule, but only in one thread at a time
+ */
 static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
 {
-	struct urb_priv *urbp, *tmp;
+	int i;
+	struct uhci_qh *qh;
 
 	/* Don't allow re-entrant calls */
 	if (uhci->scan_in_progress) {
@@ -1452,26 +1382,24 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
 	if (uhci->frame_number + uhci->is_stopped != uhci->td_remove_age)
 		uhci_free_pending_tds(uhci);
 
-	/* Walk the list of pending URBs to see which ones completed
-	 * (must be _safe because uhci_transfer_result() dequeues URBs) */
-	list_for_each_entry_safe(urbp, tmp, &uhci->urb_list, urb_list) {
-		struct urb *urb = urbp->urb;
-
-		/* Checks the status and does all of the magic necessary */
-		uhci_transfer_result(uhci, urb);
+	/* Go through all the QH queues and process the URBs in each one */
+	for (i = 0; i < UHCI_NUM_SKELQH - 1; ++i) {
+		uhci->next_qh = list_entry(uhci->skelqh[i]->node.next,
+				struct uhci_qh, node);
+		while ((qh = uhci->next_qh) != uhci->skelqh[i]) {
+			uhci->next_qh = list_entry(qh->node.next,
+					struct uhci_qh, node);
+			uhci_scan_qh(uhci, qh, regs);
+		}
 	}
-	uhci_finish_completion(uhci, regs);
-
-	/* If the controller is stopped, we can finish these off right now */
-	if (uhci->is_stopped)
-		uhci_free_pending_tds(uhci);
 
 	if (uhci->need_rescan)
 		goto rescan;
 	uhci->scan_in_progress = 0;
 
-	/* Check out the QHs waiting for unlinking */
-	uhci_scan_unlinking_qhs(uhci);
+	/* If the controller is stopped, we can finish these off right now */
+	if (uhci->is_stopped)
+		uhci_free_pending_tds(uhci);
 
 	if (list_empty(&uhci->td_remove_list) &&
 			list_empty(&uhci->skel_unlink_qh->node))
@@ -1482,19 +1410,8 @@ static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
 
 static void check_fsbr(struct uhci_hcd *uhci)
 {
-	struct urb_priv *up;
-
-	list_for_each_entry(up, &uhci->urb_list, urb_list) {
-		struct urb *u = up->urb;
-
-		spin_lock(&u->lock);
-
-		/* Check if the FSBR timed out */
-		if (up->fsbr && !up->fsbr_timeout && time_after_eq(jiffies, up->fsbrtime + IDLE_TIMEOUT))
-			uhci_fsbr_timeout(uhci, u);
-
-		spin_unlock(&u->lock);
-	}
+	/* For now, don't scan URBs for FSBR timeouts.
+	 * Add it back in later... */
 
 	/* Really disable FSBR */
 	if (!uhci->fsbr && uhci->fsbrtimeout && time_after_eq(jiffies, uhci->fsbrtimeout)) {
-- 
cgit v1.2.3-70-g09d2


From 8d402e1ae03656c1ad215514f8885ef4793f0948 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Sat, 17 Dec 2005 18:03:37 -0500
Subject: [PATCH] UHCI: improve debugging code

This patch (as626) makes some improvements to the debugging code in
uhci-hcd.  The main change is that now the code won't get compiled if
CONFIG_USB_DEBUG isn't set.  But there are other changes too, like
adding a missing .owner field and printing a debugging dump if the
controller dies.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/usb/host/uhci-debug.c | 36 +++++++++++++++++++++-----
 drivers/usb/host/uhci-hcd.c   | 60 ++++++++++++++++++++++++++++---------------
 drivers/usb/host/uhci-hcd.h   |  1 +
 drivers/usb/host/uhci-q.c     | 12 +--------
 4 files changed, 70 insertions(+), 39 deletions(-)

(limited to 'drivers/usb/host/uhci-debug.c')

diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c
index f2f5f8ce171..e1239319655 100644
--- a/drivers/usb/host/uhci-debug.c
+++ b/drivers/usb/host/uhci-debug.c
@@ -17,10 +17,13 @@
 
 #include "uhci-hcd.h"
 
-static struct dentry *uhci_debugfs_root = NULL;
+#define uhci_debug_operations (* (struct file_operations *) NULL)
+static struct dentry *uhci_debugfs_root;
+
+#ifdef DEBUG
 
 /* Handle REALLY large printks so we don't overflow buffers */
-static inline void lprintk(char *buf)
+static void lprintk(char *buf)
 {
 	char *p;
 
@@ -196,7 +199,6 @@ static int uhci_show_qh(struct uhci_qh *qh, char *buf, int len, int space)
 	return out - buf;
 }
 
-#ifdef CONFIG_PROC_FS
 static const char * const qh_names[] = {
   "skel_unlink_qh", "skel_iso_qh",
   "skel_int128_qh", "skel_int64_qh",
@@ -393,12 +395,13 @@ static int uhci_sprint_schedule(struct uhci_hcd *uhci, char *buf, int len)
 	return out - buf;
 }
 
+#ifdef CONFIG_DEBUG_FS
+
 #define MAX_OUTPUT	(64 * 1024)
 
 struct uhci_debug {
 	int size;
 	char *data;
-	struct uhci_hcd *uhci;
 };
 
 static int uhci_debug_open(struct inode *inode, struct file *file)
@@ -419,8 +422,10 @@ static int uhci_debug_open(struct inode *inode, struct file *file)
 		goto out;
 	}
 
+	up->size = 0;
 	spin_lock_irqsave(&uhci->lock, flags);
-	up->size = uhci_sprint_schedule(uhci, up->data, MAX_OUTPUT);
+	if (uhci->is_initialized)
+		up->size = uhci_sprint_schedule(uhci, up->data, MAX_OUTPUT);
 	spin_unlock_irqrestore(&uhci->lock, flags);
 
 	file->private_data = up;
@@ -472,15 +477,32 @@ static int uhci_debug_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+#undef uhci_debug_operations
 static struct file_operations uhci_debug_operations = {
+	.owner =	THIS_MODULE,
 	.open =		uhci_debug_open,
 	.llseek =	uhci_debug_lseek,
 	.read =		uhci_debug_read,
 	.release =	uhci_debug_release,
 };
 
-#else	/* CONFIG_DEBUG_FS */
+#endif	/* CONFIG_DEBUG_FS */
 
-#define uhci_debug_operations (* (struct file_operations *) NULL)
+#else	/* DEBUG */
+
+static inline void lprintk(char *buf)
+{}
+
+static inline int uhci_show_qh(struct uhci_qh *qh, char *buf,
+		int len, int space)
+{
+	return 0;
+}
+
+static inline int uhci_sprint_schedule(struct uhci_hcd *uhci,
+		char *buf, int len)
+{
+	return 0;
+}
 
 #endif
diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 9865f303d3f..4edb8330c44 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -68,12 +68,16 @@ Alan Stern"
  * debug = 3, show all TDs in URBs when dumping
  */
 #ifdef DEBUG
+#define DEBUG_CONFIGURED	1
 static int debug = 1;
-#else
-static int debug = 0;
-#endif
 module_param(debug, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(debug, "Debug level");
+
+#else
+#define DEBUG_CONFIGURED	0
+#define debug			0
+#endif
+
 static char *errbuf;
 #define ERRBUF_LEN    (32 * 1024)
 
@@ -338,6 +342,12 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
 				dev_err(uhci_dev(uhci),
 					"host controller halted, "
 					"very bad!\n");
+				if (debug > 1 && errbuf) {
+					/* Print the schedule for debugging */
+					uhci_sprint_schedule(uhci,
+							errbuf, ERRBUF_LEN);
+					lprintk(errbuf);
+				}
 				hc_died(uhci);
 
 				/* Force a callback in case there are
@@ -376,6 +386,14 @@ static void release_uhci(struct uhci_hcd *uhci)
 {
 	int i;
 
+	if (DEBUG_CONFIGURED) {
+		spin_lock_irq(&uhci->lock);
+		uhci->is_initialized = 0;
+		spin_unlock_irq(&uhci->lock);
+
+		debugfs_remove(uhci->dentry);
+	}
+
 	for (i = 0; i < UHCI_NUM_SKELQH; i++)
 		uhci_free_qh(uhci, uhci->skelqh[i]);
 
@@ -390,8 +408,6 @@ static void release_uhci(struct uhci_hcd *uhci)
 	dma_free_coherent(uhci_dev(uhci),
 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
 			uhci->frame, uhci->frame_dma_handle);
-
-	debugfs_remove(uhci->dentry);
 }
 
 static int uhci_reset(struct usb_hcd *hcd)
@@ -474,17 +490,6 @@ static int uhci_start(struct usb_hcd *hcd)
 
 	hcd->uses_new_polling = 1;
 
-	dentry = debugfs_create_file(hcd->self.bus_name,
-			S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root, uhci,
-			&uhci_debug_operations);
-	if (!dentry) {
-		dev_err(uhci_dev(uhci),
-				"couldn't create uhci debugfs entry\n");
-		retval = -ENOMEM;
-		goto err_create_debug_entry;
-	}
-	uhci->dentry = dentry;
-
 	uhci->fsbr = 0;
 	uhci->fsbrtimeout = 0;
 
@@ -495,6 +500,19 @@ static int uhci_start(struct usb_hcd *hcd)
 
 	init_waitqueue_head(&uhci->waitqh);
 
+	if (DEBUG_CONFIGURED) {
+		dentry = debugfs_create_file(hcd->self.bus_name,
+				S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root,
+				uhci, &uhci_debug_operations);
+		if (!dentry) {
+			dev_err(uhci_dev(uhci), "couldn't create uhci "
+					"debugfs entry\n");
+			retval = -ENOMEM;
+			goto err_create_debug_entry;
+		}
+		uhci->dentry = dentry;
+	}
+
 	uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
 			UHCI_NUMFRAMES * sizeof(*uhci->frame),
 			&uhci->frame_dma_handle, 0);
@@ -609,6 +627,7 @@ static int uhci_start(struct usb_hcd *hcd)
 	mb();
 
 	configure_hc(uhci);
+	uhci->is_initialized = 1;
 	start_rh(uhci);
 	return 0;
 
@@ -872,16 +891,15 @@ static int __init uhci_hcd_init(void)
 	if (usb_disabled())
 		return -ENODEV;
 
-	if (debug) {
+	if (DEBUG_CONFIGURED) {
 		errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
 		if (!errbuf)
 			goto errbuf_failed;
+		uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
+		if (!uhci_debugfs_root)
+			goto debug_failed;
 	}
 
-	uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
-	if (!uhci_debugfs_root)
-		goto debug_failed;
-
 	uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
 		sizeof(struct urb_priv), 0, 0, NULL, NULL);
 	if (!uhci_up_cachep)
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index 7e96bef2e88..4a69c7eb09b 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -411,6 +411,7 @@ struct uhci_hcd {
 	unsigned int hc_inaccessible:1;		/* HC is suspended or dead */
 	unsigned int working_RD:1;		/* Suspended root hub doesn't
 						   need to be polled */
+	unsigned int is_initialized:1;		/* Data structure is usable */
 
 	/* Support for port suspend/resume/reset */
 	unsigned long port_c_suspend;		/* Bit-arrays of ports */
diff --git a/drivers/usb/host/uhci-q.c b/drivers/usb/host/uhci-q.c
index 44bba9a6d19..5d6c4f75d0d 100644
--- a/drivers/usb/host/uhci-q.c
+++ b/drivers/usb/host/uhci-q.c
@@ -736,7 +736,6 @@ err:
 		if (errbuf) {
 			/* Print the chain for debugging purposes */
 			uhci_show_qh(urbp->qh, errbuf, ERRBUF_LEN, 0);
-
 			lprintk(errbuf);
 		}
 	}
@@ -924,26 +923,17 @@ td_error:
 	ret = uhci_map_status(status, uhci_packetout(td_token(td)));
 
 err:
-	/* 
-	 * Enable this chunk of code if you want to see some more debugging.
-	 * But be careful, it has the tendancy to starve out khubd and prevent
-	 * disconnects from happening successfully if you have a slow debug
-	 * log interface (like a serial console.
-	 */
-#if 0
 	if ((debug == 1 && ret != -EPIPE) || debug > 1) {
 		/* Some debugging code */
 		dev_dbg(uhci_dev(uhci), "%s: failed with status %x\n",
 				__FUNCTION__, status);
 
-		if (errbuf) {
+		if (debug > 1 && errbuf) {
 			/* Print the chain for debugging purposes */
 			uhci_show_qh(urbp->qh, errbuf, ERRBUF_LEN, 0);
-
 			lprintk(errbuf);
 		}
 	}
-#endif
 
 	/* Note that the queue has stopped and save the next toggle value */
 	urbp->qh->element = UHCI_PTR_TERM;
-- 
cgit v1.2.3-70-g09d2