From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:10085 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751385Ab1IZRcy (ORCPT ); Mon, 26 Sep 2011 13:32:54 -0400 Message-ID: <4E80B73F.5020804@redhat.com> Date: Mon, 26 Sep 2011 14:32:47 -0300 From: Mauro Carvalho Chehab MIME-Version: 1.0 To: Thomas Petazzoni CC: Devin Heitmueller , linux-media@vger.kernel.org, srinivasa.deevi@conexant.com, Maxime Ripard Subject: Re: cx231xx: DMA problem on ARM References: <20110921135604.64363a2e@skate> <20110922164508.395c2900@skate> <20110922172929.16df967f@skate> <20110923140404.5816c056@skate> <4E7D3D5A.6030008@redhat.com> <20110926101323.41708d64@skate> In-Reply-To: <20110926101323.41708d64@skate> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: Em 26-09-2011 05:13, Thomas Petazzoni escreveu: > Hello Mauro, > > Le Fri, 23 Sep 2011 23:15:54 -0300, > Mauro Carvalho Chehab a écrit : > >>> And still the result is the same: we get a first frame, and then >>> nothing more, and we have a large number of error messages in the >>> kernel logs. >> >> I don't think that this is related to the power manager anymore. It can >> be related to cache coherency and/or to iommu support. > > As you suspected, increasing PWR_SLEEP_INTERVAL didn't change anything. > What do you suggest to track down the potential cache coherency issues ? Take a look at the ML. The SoC people discussed a lot about cache coherency problems and how to solve it. Videobuf2 has a better support on embedded world. I would take a look on it and see what it does different than other drivers. Maybe Jonathan Corbet patches for the ccic driver may help you. It is probably a good idea to change cx231xx to use videobuf2, in order to fix this issue. Thanks, Mauro > > Best regards, > > Thomas