xhci: Reset reserved command ring TRBs on cleanup.

When the xHCI driver needs to clean up memory (perhaps due to a failed
register restore on resume from S3 or resume from S4), it needs to reset
the number of reserved TRBs on the command ring to zero.  Otherwise,
several resume cycles (about 30) with a UAS device attached will
continually increment the number of reserved TRBs, until all command
submissions fail because there isn't enough room on the command ring.

This patch should be backported to kernels as old as 2.6.32,
that contain the commit 913a8a344f
"USB: xhci: Change how xHCI commands are handled."

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Sarah Sharp 2012-05-08 07:09:26 -07:00
parent f8a9e72d12
commit 33b2831ac8
1 changed files with 1 additions and 0 deletions

View File

@ -1815,6 +1815,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
xhci->event_ring = NULL;
xhci_dbg(xhci, "Freed event ring\n");
xhci->cmd_ring_reserved_trbs = 0;
if (xhci->cmd_ring)
xhci_ring_free(xhci, xhci->cmd_ring);
xhci->cmd_ring = NULL;