From d1dc908a251c8cd87c1a1ad4f2c4a40cdbd8286c Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Fri, 9 Jul 2010 17:08:38 +0200 Subject: [PATCH] USB: xHCI: Fix another bug in link TRB activation change. Commit 6c12db90f19727c76990e7f4801c67a148b30111 also seems to have introduced a bug that is triggered when the command ring is about to wrap. The inc_enq() function will not have moved the enqueue pointer past the link TRB. It is supposed to be moved past the link TRB in prepare_ring(), which should be called before a TD is enqueued. However, the queue_command() function never calls the prepare_ring() function because prepare_ring() is only supposed to be used for endpoint rings. That means the enqueue pointer will not be moved past the link TRB, and will get overwritten. The fix is to make queue_command() call prepare_ring() with a fake endpoint status (set to running). Then the enqueue pointer will get moved past the link TRB. Signed-off-by: Sarah Sharp Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-ring.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 94e6934edb09..bfc99a939455 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2380,16 +2380,19 @@ static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2, u32 field3, u32 field4, bool command_must_succeed) { int reserved_trbs = xhci->cmd_ring_reserved_trbs; + int ret; + if (!command_must_succeed) reserved_trbs++; - if (!room_on_ring(xhci, xhci->cmd_ring, reserved_trbs)) { - if (!in_interrupt()) - xhci_err(xhci, "ERR: No room for command on command ring\n"); + ret = prepare_ring(xhci, xhci->cmd_ring, EP_STATE_RUNNING, + reserved_trbs, GFP_ATOMIC); + if (ret < 0) { + xhci_err(xhci, "ERR: No room for command on command ring\n"); if (command_must_succeed) xhci_err(xhci, "ERR: Reserved TRB counting for " "unfailable commands failed.\n"); - return -ENOMEM; + return ret; } queue_trb(xhci, xhci->cmd_ring, false, false, field1, field2, field3, field4 | xhci->cmd_ring->cycle_state);