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>
9 files changed