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authorAndiry Xu <andiry.xu@amd.com>2011-11-30 16:37:41 +0800
committerGreg Kroah-Hartman <gregkh@suse.de>2011-12-09 08:55:40 -0800
commitba92f7efc8390db5ed6da4966ef943718eb048b7 (patch)
tree10d4dc4c335e0b7697b935d1ec27ac7c3cd7d75e
parent07b91eb2d2c53017fbae33d5eae1037cb078d3e4 (diff)
xHCI: fix bug in xhci_clear_command_ring()
commit 158886cd2cf4599e04f9b7e10cb767f5f39b14f1 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-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 67900ff4146a..10dc1bdf3a71 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -657,7 +657,10 @@ 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);