path: root/drivers/usb/host
diff options
authorAlan Stern <stern@rowland.harvard.edu>2013-03-20 15:07:26 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-20 16:17:22 -0700
commitd714aaf649460cbfd5e82e75520baa856b4fa0a0 (patch)
treed155eb941ed64817d42be1c2d19ac31a6ab9b75a /drivers/usb/host
parent2726e202f7f54e69f95948f5015d39840c47e1b6 (diff)
USB: EHCI: fix regression in QH unlinking
This patch (as1670) fixes a regression caused by commit 6402c796d3b4205d3d7296157956c5100a05d7d6 (USB: EHCI: work around silicon bug in Intel's EHCI controllers). The workaround goes through two IAA cycles for each QH being unlinked. During the first cycle, the QH is not added to the async_iaa list (because it isn't fully gone from the hardware yet), which means that list will be empty. Unfortunately, I forgot to update the IAA watchdog timer routine. It thinks that an empty async_iaa list means the timer expiration was an error, which isn't true any more. This problem didn't show up during initial testing because the controllers being tested all had working IAA interrupts. But not all controllers do, and when the watchdog timer expires, the empty-list check prevents the second IAA cycle from starting. As a result, URB unlinks never complete. The check needs to be removed. Among the symptoms of the regression are processes stuck in D wait states and hangs during system shutdown. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: Stephen Warren <swarren@wwwdotorg.org> Reported-and-tested-by: Sven Joachim <svenjoac@gmx.de> Reported-by: Andreas Bombe <aeb@debian.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host')
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c
index 20dbdcbe9b0f..c3fa1305f830 100644
--- a/drivers/usb/host/ehci-timer.c
+++ b/drivers/usb/host/ehci-timer.c
@@ -304,7 +304,7 @@ static void ehci_iaa_watchdog(struct ehci_hcd *ehci)
* (a) SMP races against real IAA firing and retriggering, and
* (b) clean HC shutdown, when IAA watchdog was pending.
- if (ehci->async_iaa) {
+ if (1) {
u32 cmd, status;
/* If we get here, IAA is *REALLY* late. It's barely