From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp-vbr5.xs4all.nl ([194.109.24.25]:4192 "EHLO smtp-vbr5.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932236AbaAaRVe (ORCPT ); Fri, 31 Jan 2014 12:21:34 -0500 Message-ID: <52EBDB8B.80202@xs4all.nl> Date: Fri, 31 Jan 2014 18:21:15 +0100 From: Hans Verkuil MIME-Version: 1.0 To: Sakari Ailus CC: Laurent Pinchart , linux-media@vger.kernel.org, k.debski@samsung.com Subject: Re: [PATCH v4.1 3/3] v4l: Add V4L2_BUF_FLAG_TIMESTAMP_SOF and use it References: <201308281419.52009.hverkuil@xs4all.nl> <344618801.kmLM0jZvMY@avalon> <52A9ADF6.2090900@xs4all.nl> <18082456.iNCn4Qe0lB@avalon> <52EBC534.8080903@xs4all.nl> <20140131164233.GB15383@valkosipuli.retiisi.org.uk> In-Reply-To: <20140131164233.GB15383@valkosipuli.retiisi.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Sakari, On 01/31/2014 05:42 PM, Sakari Ailus wrote: > Hi Hans and Laurent, > > On Fri, Jan 31, 2014 at 04:45:56PM +0100, Hans Verkuil wrote: >> How about defining a capability for use with ENUMINPUT/OUTPUT? I agree that this >> won't change between buffers, but it is a property of a specific input or output. > > Over 80 characters per line. :-P Stupid thunderbird doesn't show the column, and I can't enable automatic word-wrap because that plays hell with patches. Solutions welcome! > >> There are more than enough bits available in v4l2_input/output to add one for >> SOF timestamps. > > In complex devices with a non-linear media graph inputs and outputs are not > very relevant, and for that reason many drivers do not even implement them. > I'd rather not bind video buffer queues to inputs or outputs. Then we end up again with buffer flags. It's a property of the selected input or output, so if you can't/don't want to use that, then it's buffer flags. Which I like as well, but it's probably useful that the documentation states that it can only change if the input or output changes as well. > My personal favourite is still to use controls for the purpose but the > buffer flags come close, too, especially now that we're using them for > timestamp sources. Laurent, can we please end this discussion? It makes perfect sense to store this information as a BUF_FLAG IMHO. You can just do a QUERYBUF once after you called REQBUFS and you know what you have to deal with. Regards, Hans