From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from eu1sys200aog114.obsmtp.com ([207.126.144.137]:52279 "EHLO eu1sys200aog114.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946359Ab3BHMoD (ORCPT ); Fri, 8 Feb 2013 07:44:03 -0500 Message-ID: <5114F2F4.5040702@stericsson.com> Date: Fri, 8 Feb 2013 13:43:32 +0100 From: Marcus Lorentzon MIME-Version: 1.0 To: Tomi Valkeinen Cc: Laurent Pinchart , Tomasz Figa , Thomas Petazzoni , "linux-fbdev@vger.kernel.org" , Philipp Zabel , Tom Gall , Ragesh Radhakrishnan , "dri-devel@lists.freedesktop.org" , Rob Clark , Kyungmin Park , sunil joshi , Benjamin Gaignard , Bryan Wu , Maxime Ripard , Vikas Sajjan , Sumit Semwal , Sebastien Guiriec , "linux-media@vger.kernel.org" Subject: Re: [RFC v2 0/5] Common Display Framework References: <1353620736-6517-1-git-send-email-laurent.pinchart@ideasonboard.com> <1987992.4TmVjQaiLj@amdc1227> <50EC5283.80006@stericsson.com> <3057999.UZLp2j2DkQ@avalon> <510F8807.2020406@stericsson.com> <5114D8A2.6010806@ti.com> In-Reply-To: <5114D8A2.6010806@ti.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 02/08/2013 11:51 AM, Tomi Valkeinen wrote: > On 2013-02-04 12:05, Marcus Lorentzon wrote: > >> As discussed at FOSDEM I will give DSI bus with full feature set a >> try. > Please do, but as a reminder I want to raise the issues I see with a DSI > bus: > > - A device can be a child of only one bus. So if DSI is used only for > video, the device is a child of, say, i2c bus, and thus there's no DSI > bus. How to configure and use DSI in this case? > > - If DSI is used for both control and video, we have two separate APIs > for the bus. What I mean here is that for the video-only case above, we > need a video-only-API for DSI. This API should contain all necessary > methods to configure DSI. But we need similar methods for the control > API also. > > So, I hope you come up with some solution for this, but as I see it, > it's easily the most simple and clear option to have one video_source > style entity for the DSI bus itself, which is used for both control and > video. > > Thanks, it is not that I'm totally against the video source stuff. And I share your concerns, none of the solutions are perfect. It just doesn't feel right to create this dummy source "device" without investigating the DSI bus route. But I will try to write up some history/problem description and ask Greg KH for guidance. If he has a strong opinion either way, there is not much more to discuss ;) /BR /Marcus From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcus Lorentzon Date: Fri, 08 Feb 2013 12:43:32 +0000 Subject: Re: [RFC v2 0/5] Common Display Framework Message-Id: <5114F2F4.5040702@stericsson.com> List-Id: References: <1353620736-6517-1-git-send-email-laurent.pinchart@ideasonboard.com> <1987992.4TmVjQaiLj@amdc1227> <50EC5283.80006@stericsson.com> <3057999.UZLp2j2DkQ@avalon> <510F8807.2020406@stericsson.com> <5114D8A2.6010806@ti.com> In-Reply-To: <5114D8A2.6010806@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tomi Valkeinen Cc: Laurent Pinchart , Tomasz Figa , Thomas Petazzoni , "linux-fbdev@vger.kernel.org" , Philipp Zabel , Tom Gall , Ragesh Radhakrishnan , "dri-devel@lists.freedesktop.org" , Rob Clark , Kyungmin Park , sunil joshi , Benjamin Gaignard , Bryan Wu , Maxime Ripard , Vikas Sajjan , Sumit Semwal , Sebastien Guiriec , "linux-media@vger.kernel.org" On 02/08/2013 11:51 AM, Tomi Valkeinen wrote: > On 2013-02-04 12:05, Marcus Lorentzon wrote: > >> As discussed at FOSDEM I will give DSI bus with full feature set a >> try. > Please do, but as a reminder I want to raise the issues I see with a DSI > bus: > > - A device can be a child of only one bus. So if DSI is used only for > video, the device is a child of, say, i2c bus, and thus there's no DSI > bus. How to configure and use DSI in this case? > > - If DSI is used for both control and video, we have two separate APIs > for the bus. What I mean here is that for the video-only case above, we > need a video-only-API for DSI. This API should contain all necessary > methods to configure DSI. But we need similar methods for the control > API also. > > So, I hope you come up with some solution for this, but as I see it, > it's easily the most simple and clear option to have one video_source > style entity for the DSI bus itself, which is used for both control and > video. > > Thanks, it is not that I'm totally against the video source stuff. And I share your concerns, none of the solutions are perfect. It just doesn't feel right to create this dummy source "device" without investigating the DSI bus route. But I will try to write up some history/problem description and ask Greg KH for guidance. If he has a strong opinion either way, there is not much more to discuss ;) /BR /Marcus