3.6.11.2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern [ Upstream commit d714aaf649460cbfd5e82e75520baa856b4fa0a0 ] 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 Reported-and-tested-by: Stephen Warren Reported-and-tested-by: Sven Joachim Reported-by: Andreas Bombe Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Steven Rostedt --- drivers/usb/host/ehci-timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/host/ehci-timer.c b/drivers/usb/host/ehci-timer.c index 20dbdcb..c3fa130 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 -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/