summaryrefslogtreecommitdiffstats
path: root/drivers/usb/host/ehci-hcd.c
diff options
context:
space:
mode:
authorAlan Stern <stern@rowland.harvard.edu>2012-07-11 11:21:54 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-07-16 16:53:16 -0700
commitd58b4bcc6df8046cf9c3c59f9ff84d2cd86b93eb (patch)
treebef387c0c81654a38271f8528bb8b877ac5d3ed7 /drivers/usb/host/ehci-hcd.c
parentc0c53dbc32ea05a1e1dd9dba4772327da9a11750 (diff)
USB: EHCI: introduce high-res timer
This patch (as1572) begins the conversion of ehci-hcd over to using high-resolution timers rather than old-fashioned low-resolution kernel timers. This reduces overhead caused by timer roundoff on systems where HZ is smaller than 1000. Also, the new timer framework introduced here is much more logical and easily extended than the ad-hoc approach ehci-hcd currently uses for timers. An hrtimer structure is added to ehci_hcd, along with a bitflag array and an array of ktime_t values, to keep track of which timing events are pending and what their expiration times are. Only the infrastructure for the timing operations is added in this patch. Later patches will add routines for handling each of the various timing events the driver needs. In some cases the new hrtimer handlers will replace the existing handlers for ehci-hcd's kernel timers; as this happens the old timers will be removed. In other cases the new timing events will replace busy-wait loops. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/ehci-hcd.c')
-rw-r--r--drivers/usb/host/ehci-hcd.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index bc94822f4c5..f8fed163a23 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -30,8 +30,7 @@
#include <linux/vmalloc.h>
#include <linux/errno.h>
#include <linux/init.h>
-#include <linux/timer.h>
-#include <linux/ktime.h>
+#include <linux/hrtimer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/usb.h>
@@ -380,6 +379,7 @@ static void ehci_quiesce (struct ehci_hcd *ehci)
static void end_unlink_async(struct ehci_hcd *ehci);
static void ehci_work(struct ehci_hcd *ehci);
+#include "ehci-timer.c"
#include "ehci-hub.c"
#include "ehci-lpm.c"
#include "ehci-mem.c"
@@ -494,7 +494,10 @@ static void ehci_shutdown(struct usb_hcd *hcd)
spin_lock_irq(&ehci->lock);
ehci->rh_state = EHCI_RH_STOPPING;
ehci_silence_controller(ehci);
+ ehci->enabled_hrtimer_events = 0;
spin_unlock_irq(&ehci->lock);
+
+ hrtimer_cancel(&ehci->hrtimer);
}
static void ehci_port_power (struct ehci_hcd *ehci, int is_on)
@@ -561,12 +564,14 @@ static void ehci_stop (struct usb_hcd *hcd)
del_timer_sync(&ehci->iaa_watchdog);
spin_lock_irq(&ehci->lock);
+ ehci->enabled_hrtimer_events = 0;
ehci_quiesce(ehci);
ehci_silence_controller(ehci);
ehci_reset (ehci);
spin_unlock_irq(&ehci->lock);
+ hrtimer_cancel(&ehci->hrtimer);
remove_sysfs_files(ehci);
remove_debug_files (ehci);
@@ -615,6 +620,10 @@ static int ehci_init(struct usb_hcd *hcd)
ehci->iaa_watchdog.function = ehci_iaa_watchdog;
ehci->iaa_watchdog.data = (unsigned long) ehci;
+ hrtimer_init(&ehci->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ ehci->hrtimer.function = ehci_hrtimer_func;
+ ehci->next_hrtimer_event = EHCI_HRTIMER_NO_EVENT;
+
hcc_params = ehci_readl(ehci, &ehci->caps->hcc_params);
/*
@@ -954,6 +963,8 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
dbg_status(ehci, "fatal", status);
ehci_halt(ehci);
dead:
+ ehci->enabled_hrtimer_events = 0;
+ hrtimer_try_to_cancel(&ehci->hrtimer);
ehci_reset(ehci);
ehci_writel(ehci, 0, &ehci->regs->configured_flag);
usb_hc_died(hcd);