From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <55015297.5080406@linux.intel.com> Date: Thu, 12 Mar 2015 16:47:19 +0800 From: "Lu, Baolu" MIME-Version: 1.0 To: Mathias Nyman , Mathias Nyman , Greg Kroah-Hartman CC: dheitmueller@kernellabs.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 1/1] usb: xhci: apply XHCI_AVOID_BEI quirk to Intel ValleyView and LynxPoint LP References: <1426124346-23365-1-git-send-email-baolu.lu@linux.intel.com> <55015267.4050108@linux.intel.com> In-Reply-To: <55015267.4050108@linux.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On 03/12/2015 04:46 PM, Mathias Nyman wrote: > On 12.03.2015 03:39, 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.") >> > Maybe we should set the quirk for all Intel xHCI controllers. > So far the list includes Pantherpoint, Lynxpoint and valleyview. > > I bet it concerns most Intel platforms. Yes, I agree with you. I will send out a new patch for this. > > -Mathias > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >