From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.free-electrons.com ([88.190.12.23]:44154 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751385Ab1IZUAD convert rfc822-to-8bit (ORCPT ); Mon, 26 Sep 2011 16:00:03 -0400 Date: Mon, 26 Sep 2011 21:59:54 +0200 From: Thomas Petazzoni To: Laurent Pinchart Cc: Mauro Carvalho Chehab , Devin Heitmueller , linux-media@vger.kernel.org, srinivasa.deevi@conexant.com, Maxime Ripard Subject: Re: cx231xx: DMA problem on ARM Message-ID: <20110926215954.5ab059e4@skate> In-Reply-To: <201109262102.49056.laurent.pinchart@ideasonboard.com> References: <20110921135604.64363a2e@skate> <20110926101323.41708d64@skate> <4E80B73F.5020804@redhat.com> <201109262102.49056.laurent.pinchart@ideasonboard.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-media-owner@vger.kernel.org List-ID: Hello Laurent, Le Mon, 26 Sep 2011 21:02:48 +0200, Laurent Pinchart a écrit : > Are you using the MMAP or USERPTR capture method ? If using MMAP, can > you try (as a test only) to unmap the buffer before queueing it and > to remap it after dequeuing it ? So far, we have used VLC, Cheese, or a simple OpenCV based application to test the V4L2 device on our ARM platform, and I have no idea which capture method those are using. Is there a very simple V4L test application that we could use to hack the buffer unmap/remap trick you're suggesting as a test ? Regards, Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com