Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941071AbcKXNQ7 (ORCPT ); Thu, 24 Nov 2016 08:16:59 -0500 Received: from mail-wm0-f49.google.com ([74.125.82.49]:37681 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938550AbcKXNQx (ORCPT ); Thu, 24 Nov 2016 08:16:53 -0500 Subject: Re: [PATCH v3 4/9] media: venus: vdec: add video decoder files To: nicolas@ndufresne.ca, Stanimir Varbanov , Hans Verkuil , Mauro Carvalho Chehab References: <1478540043-24558-1-git-send-email-stanimir.varbanov@linaro.org> <1478540043-24558-5-git-send-email-stanimir.varbanov@linaro.org> <63a91a5a-a97b-f3df-d16d-c8f76bf20c30@xs4all.nl> <4ec31084-1720-845a-30f6-60ddfe285ff1@linaro.org> <86442d1d-4a12-71c1-97fa-12bc73bb5045@linaro.org> <9ff4f3cf-f6d1-cebe-6f1a-e4209c55e4f4@xs4all.nl> <15975057-dd6a-6946-07ac-93a748b6a176@linaro.org> <113772f1-8eb9-dd44-42c6-4f109200dff7@linaro.org> <1479932682.29275.1.camel@ndufresne.ca> Cc: Andy Gross , Bjorn Andersson , Stephen Boyd , Srinivas Kandagatla , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org From: Stanimir Varbanov Message-ID: <6d0d477f-22c7-5315-6eae-027a2525345c@linaro.org> Date: Thu, 24 Nov 2016 15:16:16 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <1479932682.29275.1.camel@ndufresne.ca> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1267 Lines: 40 Hi Nicolas, On 11/23/2016 10:24 PM, Nicolas Dufresne wrote: > Le lundi 21 novembre 2016 à 18:09 +0200, Stanimir Varbanov a écrit : >>>> Meanwhile I have found bigger obstacle - I cannot run multiple >> instances >>>> simultaneously. By m2m design it can execute only one job (m2m >> context) >>>> at a time per m2m device. Can you confirm that my observation is >> correct? >>> >>> The m2m framework assumes a single HW instance, yes. Do you have >> multiple >>> HW decoders? I might not understand what you mean... >>> >> >> I mean that I can start and execute up to 16 decoder sessions >> simultaneously. Its a firmware responsibility how those sessions are >> scheduled and how the hardware is shared between them. Of course >> depending on the resolution the firmware can refuse to start the >> session >> because the hardware will be overloaded and will not be able to >> satisfy >> the bitrate requirements. > > This is similar to S5P-MFC driver, which you may have notice not use > m2m framework. Thanks for the note. I have started to look into m2m because Hans asked me to reuse the ioctl helpers that it provides. I have no problem with usage of the m2m API if they help me to reduce code size and doesn't impact performance. -- regards, Stan