From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail2.matrix-vision.com ([85.214.244.251]:54098 "EHLO mail2.matrix-vision.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752264Ab2GCJoa (ORCPT ); Tue, 3 Jul 2012 05:44:30 -0400 Message-ID: <4FF2BF79.2020302@matrix-vision.de> Date: Tue, 03 Jul 2012 11:46:33 +0200 From: Michael Jones MIME-Version: 1.0 To: linux-media ML CC: Laurent Pinchart Subject: capture_mem limitations in OMAP ISP Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Laurent & co., I'm looking at the memory limitations in the omap3isp driver. 'struct isp_video' contains member 'capture_mem', which is set separately for each of our v4l2 video device nodes. The CCDC, for example, has capture_mem = 4096 * 4096 * 3 = 48MB, while the previewer and resizer each have twice that. Where do these numbers come from? Is the CCDC incapable of DMA'ing more than 48MB into memory? I know that ISP_VIDEO_MAX_BUFFERS also limits the # of buffers, but I assume this is basically an arbitrary number so we can have a finite array of isp_video_buffer's. The 48MB, on the other hand, looks like it might have a good reason. thanks, Michael MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner, Erhard Meier