USB: xhci: Notify the xHC when a device is reset.

When a USB device is reset, the xHCI hardware must know, in order to match
the device state and disable all endpoints except control endpoint 0.
Issue a Reset Device command after a USB device is successfully reset.
Wait on the command to finish, and then cache or free the disabled
endpoint rings.

There are four different USB device states that the xHCI hardware tracks:
 - disabled/enabled - device connection has just been detected,
 - default - the device has been reset and has an address of 0,
 - addressed - the device has a non-zero address but no configuration has
   been set,
 - configured - a set configuration succeeded.

The USB core may issue a port reset when a device is in any state, but the
Reset Device command will fail for a 0.96 xHC if the device is not in the
addressed or configured state.  Don't consider this failure as an error,
but don't free any endpoint rings if this command fails.

A storage driver may request that the USB device be reset during error
handling, so use GPF_NOIO instead of GPF_KERNEL while allocating memory
for the Reset Device command.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-dbg.c b/drivers/usb/host/xhci-dbg.c
index 33128d52f21..b2915aea47e 100644
--- a/drivers/usb/host/xhci-dbg.c
+++ b/drivers/usb/host/xhci-dbg.c
@@ -406,6 +406,25 @@ static void dbg_rsvd64(struct xhci_hcd *xhci, u64 *ctx, dma_addr_t dma)
 	}
 }
 
+inline char *xhci_get_slot_state(struct xhci_hcd *xhci,
+		struct xhci_container_ctx *ctx)
+{
+	struct xhci_slot_ctx *slot_ctx = xhci_get_slot_ctx(xhci, ctx);
+
+	switch (GET_SLOT_STATE(slot_ctx->dev_state)) {
+	case 0:
+		return "enabled/disabled";
+	case 1:
+		return "default";
+	case 2:
+		return "addressed";
+	case 3:
+		return "configured";
+	default:
+		return "reserved";
+	}
+}
+
 void xhci_dbg_slot_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx)
 {
 	/* Fields are 32 bits wide, DMA addresses are in bytes */