From d7fb5c3789e6b3f7d02b2b26e559b043c970ed91 Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Tue, 16 Aug 2016 10:18:03 +0300 Subject: xhci: always handle "Command Ring Stopped" events [ Upstream commit 33be126510974e2eb9679f1ca9bca4f67ee4c4c7 ] Fix "Command completion event does not match command" errors by always handling the command ring stopped events. The command ring stopped event is generated as a result of aborting or stopping the command ring with a register write. It is not caused by a command in the command queue, and thus won't have a matching command in the comman list. Solve it by handling the command ring stopped event before checking for a matching command. In most command time out cases we abort the command ring, and get a command ring stopped event. The events command pointer will point at the current command ring dequeue, which in most cases matches the timed out command in the command list, and no error messages are seen. If we instead get a command aborted event before the command ring stopped event, the abort event will increse the command ring dequeue pointer, and the following command ring stopped events command pointer will point at the next, not yet queued command. This case triggered the error message Signed-off-by: Mathias Nyman CC: Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/host/xhci-ring.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 69464630be54..51ff57497b91 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1324,12 +1324,6 @@ static void handle_cmd_completion(struct xhci_hcd *xhci, cmd = list_entry(xhci->cmd_list.next, struct xhci_command, cmd_list); - if (cmd->command_trb != xhci->cmd_ring->dequeue) { - xhci_err(xhci, - "Command completion event does not match command\n"); - return; - } - del_timer(&xhci->cmd_timer); trace_xhci_cmd_completion(cmd_trb, (struct xhci_generic_trb *) event); @@ -1341,6 +1335,13 @@ static void handle_cmd_completion(struct xhci_hcd *xhci, xhci_handle_stopped_cmd_ring(xhci, cmd); return; } + + if (cmd->command_trb != xhci->cmd_ring->dequeue) { + xhci_err(xhci, + "Command completion event does not match command\n"); + return; + } + /* * Host aborted the command ring, check if the current command was * supposed to be aborted, otherwise continue normally. -- cgit v1.2.3