From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from comal.ext.ti.com ([198.47.26.152]:34414 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752320AbcKAUeK (ORCPT ); Tue, 1 Nov 2016 16:34:10 -0400 Date: Tue, 1 Nov 2016 15:33:46 -0500 From: Bin Liu To: "Matwey V. Kornilov" CC: Alan Stern , , , Subject: Re: musb: isoc pkt loss with pwc Message-ID: <20161101203346.GE30087@uda0271908> References: <20160830183039.GA20056@uda0271908> <20160912032826.GB18340@uda0271908> <20160912185709.GL18340@uda0271908> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: Sender: linux-media-owner@vger.kernel.org List-ID: On Sat, Oct 15, 2016 at 10:25:42PM +0300, Matwey V. Kornilov wrote: [snip] > >>> > Which means without this commit your camera has been working without > >>> > issues, and this is a regression with this commit, right? > >>> > > >>> > >>> Right > >> > >> Okay, thanks for confirming. > >> > >> But we cannot just simply add this flag, as it breaks many other use > >> cases. I will continue work on this to find a solution which works on > >> all use cases. > >> > > > > Ok, thank you. > > > > Excuse me. Any news? Not solved yet. I used uvc class to exam the issue. uvc_video driver takes longer time to execute urb complete() on my platform. Using HCD_BH flag doesn't help, because urb->complete() was running with irq disabled because of the local_irq. Removing the local_irq as in [1] causes the system to lockup - uart and network stop responsing, so hard to debug for now. Right now, I added a workqueue in musb_host to handle urb->complete() with local_irq removed. It seems working fine in my test, but it is still a long way find the proper fix for upstream. I didn't have much time on this issue. Once I have a proper solution, I will post it to the mailing list. [1] http://marc.info/?l=linux-usb&m=147560701431267&w=2 Regards, -Bin.