From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69F04C28CF6 for ; Thu, 26 Jul 2018 10:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2173E20846 for ; Thu, 26 Jul 2018 10:36:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2173E20846 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729346AbeGZLxC (ORCPT ); Thu, 26 Jul 2018 07:53:02 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:55067 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729111AbeGZLxC (ORCPT ); Thu, 26 Jul 2018 07:53:02 -0400 Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1fiddV-00039m-2u; Thu, 26 Jul 2018 12:36:45 +0200 Message-ID: <1532601401.4879.10.camel@pengutronix.de> Subject: Re: [PATCH 1/2] media: docs-rst: Document memory-to-memory video decoder interface From: Philipp Zabel To: Tomasz Figa , Hans Verkuil Cc: Linux Media Mailing List , Linux Kernel Mailing List , Stanimir Varbanov , Mauro Carvalho Chehab , Pawel Osciak , Alexandre Courbot , kamil@wypas.org, a.hajda@samsung.com, Kyungmin Park , jtp.park@samsung.com, Tiffany Lin =?UTF-8?Q?=28=E6=9E=97=E6=85=A7=E7=8F=8A=29?= , Andrew-CT Chen =?UTF-8?Q?=28=E9=99=B3=E6=99=BA=E8=BF=AA=29?= , todor.tomov@linaro.org, nicolas@ndufresne.ca, Paul Kocialkowski , Laurent Pinchart , dave.stevenson@raspberrypi.org, Ezequiel Garcia Date: Thu, 26 Jul 2018 12:36:41 +0200 In-Reply-To: References: <20180724140621.59624-1-tfiga@chromium.org> <20180724140621.59624-2-tfiga@chromium.org> <37a8faea-a226-2d52-36d4-f9df194623cc@xs4all.nl> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2018-07-26 at 19:20 +0900, Tomasz Figa wrote: [...] > > You might want to mention that if there are insufficient buffers, then > > VIDIOC_CREATE_BUFS can be used to add more buffers. > > > > This might be a bit tricky, since at least s5p-mfc and coda can only > work on a fixed buffer set and one would need to fully reinitialize > the decoding to add one more buffer, which would effectively be the > full resolution change sequence, as below, just with REQBUFS(0), > REQBUFS(N) replaced with CREATE_BUFS. The coda driver supports CREATE_BUFS on the decoder CAPTURE queue. The firmware indeed needs a fixed frame buffer set, but these buffers are internal only and in a coda specific tiling format. The content of finished internal buffers is copied / detiled into the external CAPTURE buffers, so those can be added at will. regards Philipp