On 03/12/2015 03:54 PM, Greg Kroah-Hartman wrote:
On Thu, Mar 12, 2015 at 09:39:06AM +0800, Lu Baolu wrote:When a device with an isochronous endpoint is plugged into the Intel xHCI host controller, and the driver submits multiple frames per URB, the xHCI driver will set the Block Event Interrupt (BEI) flag on all but the last TD for the URB. This causes the host controller to place an event on the event ring, but not send an interrupt. When the last TD for the URB completes, BEI is cleared, and we get an interrupt for the whole URB. However, under some Intel xHCI host controllers like ValleyView and Lynx Point LP, if the event ring is full of events from transfers with BEI set, a "Event Ring is Full" event will be posted to the last entry of the event ring, but no interrupt is generated. Host will cease all transfer and command executions and wait until software completes handling the pending events in event ring. That means xHC stops but event of "event ring is full" is not notified. As the result, the xHC looks like dead to user. The patch is to apply XHCI_AVOID_BEI to Intel VallyView and Lynx Point LP devices. And it should be backported to kernels as old as 3.0, that contains the commit 69e848c2090a ("Intel xhci: Support EHCI/xHCI port switching.") Signed-off-by: Lu Baolu <baolu...@linux.intel.com> Cc: sta...@vger.kernel.org --- drivers/usb/host/xhci-pci.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index fd53c9e..5aa4893 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -40,6 +40,7 @@ #define PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI 0x22b5 #define PCI_DEVICE_ID_INTEL_SUNRISEPOINT_H_XHCI 0xa12f #define PCI_DEVICE_ID_INTEL_SUNRISEPOINT_LP_XHCI 0x9d2f +#define PCI_DEVICE_ID_INTEL_VALLEYVIEW_XHCI 0x0f35Minor nit, you added a tab where the rest of the file was using a space :(
Yes, thanks for reminding.
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