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authorAndiry Xu <andiry.xu@amd.com>2011-11-30 16:37:41 +0800
committerSarah Sharp <sarah.a.sharp@linux.intel.com>2011-12-01 10:38:27 -0800
commit158886cd2cf4599e04f9b7e10cb767f5f39b14f1 (patch)
treef59d102f1460155cfb49d5fdff8da762a5dde533 /drivers/usb
parent6414e94c203d92b163ca61b5f51a25b80a621dbe (diff)
downloadvexpress-lsk-158886cd2cf4599e04f9b7e10cb767f5f39b14f1.tar.gz
xHCI: fix bug in xhci_clear_command_ring()
When system enters suspend, xHCI driver clears command ring by writing zero to all the TRBs. However, this also writes zero to the Link TRB, and the ring is mangled. This may cause driver accesses wrong memory address and the result is unpredicted. When clear the command ring, keep the last Link TRB intact, only clear its cycle bit. This should fix the "command ring full" issue reported by Oliver Neukum. This should be backported to stable kernels as old as 2.6.37, since the commit 89821320 "xhci: Fix command ring replay after resume" is merged. Signed-off-by: Andiry Xu <andiry.xu@amd.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Reported-by: Oliver Neukum <oneukum@suse.de>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/xhci.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index aa94c019579..a1afb7c39f7 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -711,7 +711,10 @@ static void xhci_clear_command_ring(struct xhci_hcd *xhci)
ring = xhci->cmd_ring;
seg = ring->deq_seg;
do {
- memset(seg->trbs, 0, SEGMENT_SIZE);
+ memset(seg->trbs, 0,
+ sizeof(union xhci_trb) * (TRBS_PER_SEGMENT - 1));
+ seg->trbs[TRBS_PER_SEGMENT - 1].link.control &=
+ cpu_to_le32(~TRB_CYCLE);
seg = seg->next;
} while (seg != ring->deq_seg);