From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id mAQ0D42V018561 for ; Tue, 25 Nov 2008 19:13:04 -0500 Received: from smtp6-g19.free.fr (smtp6-g19.free.fr [212.27.42.36]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id mAQ0CoEX006993 for ; Tue, 25 Nov 2008 19:12:50 -0500 To: Mike Rapoport References: <87prl4x28e.fsf@free.fr> <491C002F.4070804@compulab.co.il> <87ljvktqtv.fsf@free.fr> <491FCBFF.9060208@compulab.co.il> From: Robert Jarzmik Date: Tue, 25 Nov 2008 22:18:46 +0100 In-Reply-To: <491FCBFF.9060208@compulab.co.il> (Mike Rapoport's message of "Sun\, 16 Nov 2008 09\:30\:07 +0200") Message-ID: <87ljv7a4i1.fsf@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: video4linux-list@redhat.com Subject: Re: pxa_camera: DMA alignment requirement List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: video4linux-list-bounces@redhat.com Errors-To: video4linux-list-bounces@redhat.com List-ID: Mike Rapoport writes: >>>>From what I read on the PXA manual, the only constraint is 16bytes >> alignement. Would you also remember who wrote the code, so that I can ask him >> where he read about page alignement constraint please ? > > Just by coincidence it was me :) > I used pxafb_overlay from [1], and my (mis)understanding of what it does added > the page alignment constrain. Now looking at the overlay code once more, I'm not > sure if it's necessary. > > --- > [1] http://www.rpsys.net/openzaurus/patches/archive/pxa27x_overlay-r8.patch Just for the record, I made a try or two, changing the alignment from page (4096 bytes) into 16 bytes (PAGE_ALIGN -> ALIGN(x,16)). And surprise, I get a lot of DMA bus errors ... I'm still investigating, there's something weird in there ... Cheers. -- Robert -- video4linux-list mailing list Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe https://www.redhat.com/mailman/listinfo/video4linux-list