From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-yw0-f193.google.com ([209.85.161.193]:36301 "EHLO mail-yw0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932750AbdA0RQl (ORCPT ); Fri, 27 Jan 2017 12:16:41 -0500 MIME-Version: 1.0 In-Reply-To: <20161101203346.GE30087@uda0271908> References: <20160830183039.GA20056@uda0271908> <20160912032826.GB18340@uda0271908> <20160912185709.GL18340@uda0271908> <20161101203346.GE30087@uda0271908> From: "Matwey V. Kornilov" Date: Fri, 27 Jan 2017 20:13:23 +0300 Message-ID: Subject: Re: musb: isoc pkt loss with pwc To: Bin Liu , "Matwey V. Kornilov" , Alan Stern , hdegoede@redhat.com, linux-media@vger.kernel.org, linux-usb@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-media-owner@vger.kernel.org List-ID: 2016-11-01 23:33 GMT+03:00 Bin Liu : > 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. > Maybe I could help somehow? > [1] http://marc.info/?l=linux-usb&m=147560701431267&w=2 > > Regards, > -Bin. > -- With best regards, Matwey V. Kornilov. Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia 119991, Moscow, Universitetsky pr-k 13, +7 (495) 9392382