USB: EHCI: update toggle state for linked QHs

This patch (as1245) fixes a bug in ehci-hcd.  When an URB is queued
for an endpoint whose QH is already in the LINKED state, the QH
doesn't get refreshed.  As a result, if usb_clear_halt() was called
during the time that the QH was linked but idle, the data toggle value
in the QH doesn't get reset.

The symptom is that after a clear_halt, data gets lost and transfers
time out.  This problem is starting to show up now because the
"ehci-hcd unlink speedups" patch causes QHs with no queued URBs to
remain linked for a suitable time.

The patch utilizes the new endpoint_reset mechanism to fix the
problem.  When an endpoint is reset, the new method forcibly unlinks
the QH (if necessary) and safely updates the toggle value.  This
allows qh_update() to be simplified and avoids using usb_device's
toggle bits in a rather unintuitive way.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Tested-by: David <david@unsolicited.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-ixp4xx.c b/drivers/usb/host/ehci-ixp4xx.c
index 9c32063a0c2f..a44bb4a94954 100644
--- a/drivers/usb/host/ehci-ixp4xx.c
+++ b/drivers/usb/host/ehci-ixp4xx.c
@@ -51,6 +51,7 @@ static const struct hc_driver ixp4xx_ehci_hc_driver = {
         .urb_enqueue            = ehci_urb_enqueue,
         .urb_dequeue            = ehci_urb_dequeue,
         .endpoint_disable       = ehci_endpoint_disable,
+        .endpoint_reset         = ehci_endpoint_reset,
         .get_frame_number       = ehci_get_frame,
         .hub_status_data        = ehci_hub_status_data,
         .hub_control            = ehci_hub_control,