From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail1.bemta12.messagelabs.com ([216.82.251.14]:37272 "EHLO mail1.bemta12.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750962AbaDOGLq convert rfc822-to-8bit (ORCPT ); Tue, 15 Apr 2014 02:11:46 -0400 Message-ID: <534CCBF3.8030409@barco.com> Date: Tue, 15 Apr 2014 08:04:35 +0200 From: Thomas Scheuermann MIME-Version: 1.0 To: Laurent Pinchart CC: "linux-media@vger.kernel.org" Subject: Re: AW: AW: v4l2_buffer with PBO mapped memory References: <533C2872.5090603@barco.com> <82154683.DEhQIaoLxb@avalon> <67C778DDEF97AE4BA9DC4BA8ECFD811E1DB2EA13@KUUMEX11.barco.com> <12148246.7IO9AkCti4@avalon> <53478425.1010502@barco.com> In-Reply-To: <53478425.1010502@barco.com> Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7BIT Sender: linux-media-owner@vger.kernel.org List-ID: Hi Laurent, On 11.04.2014 07:56, Thomas Scheuermann wrote: > Hi Laurent, > > On 07.04.2014 01:37, Laurent Pinchart wrote: >> Hi Thomas, >> >> On Friday 04 April 2014 20:01:33 Scheuermann, Mail wrote: >>> Hi Laurent, >>> >>> I've done the following: >>> >>> echo 3 >/sys/module/videobuf2_core/parameters/debug >>> >>> and found in /var/log/kern.log after starting my program: >>> >>> [239432.535077] vb2: Buffer 0, plane 0 offset 0x00000000 >>> [239432.535080] vb2: Buffer 1, plane 0 offset 0x001c2000 >>> [239432.535082] vb2: Buffer 2, plane 0 offset 0x00384000 >>> [239432.535083] vb2: Allocated 3 buffers, 1 plane(s) each >>> [239432.535085] vb2: qbuf: userspace address for plane 0 changed, >>> reacquiring memory >>> [239432.535087] vb2: qbuf: failed acquiring userspace memory for >>> plane 0 >> This confirms everything is working properly up to the point where >> videobuf2- >> vmalloc fails to acquire the user pointer memory. The problem comes from >> vb2_vmalloc_get_userptr() in >> drivers/media/v4l2-core/videobuf2-vmalloc.c. >> Unfortunately that function lacks debugging. Are you familiar enough >> with >> kernel programming to add printk statements there and see where it >> fails ? > I was able to put some debug output in vb2_vmalloc_get_userptr. > A call to 'vb2_get_contig_userptr' failed. > I will also put some debug code there to get more information. In vb2_get_contig_userptr I saw that the call to 'follow_pfn' failed and returned -22. Do you know what the problem here is? >>> [239432.535088] vb2: qbuf: buffer preparation failed: -22 >>> [239432.535128] vb2: streamoff: not streaming > > This message is subject to the following terms and conditions: MAIL > DISCLAIMER > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html This message is subject to the following terms and conditions: MAIL DISCLAIMER