From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ee0-f46.google.com ([74.125.83.46]:44429 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753573Ab2IGUAN (ORCPT ); Fri, 7 Sep 2012 16:00:13 -0400 Received: by eekc1 with SMTP id c1so1418058eek.19 for ; Fri, 07 Sep 2012 13:00:12 -0700 (PDT) Message-ID: <504A5249.4000602@gmail.com> Date: Fri, 07 Sep 2012 22:00:09 +0200 From: Sylwester Nawrocki MIME-Version: 1.0 To: Hans Verkuil CC: linux-media@vger.kernel.org, Laurent Pinchart , Hans Verkuil Subject: Re: [RFCv2 API PATCH 04/28] DocBook: make the G/S/TRY_FMT specification more strict. References: <1347024568-32602-1-git-send-email-hverkuil@xs4all.nl> <5c449812e54fff0816282e712ab9e24c8b278cb6.1347023744.git.hans.verkuil@cisco.com> In-Reply-To: <5c449812e54fff0816282e712ab9e24c8b278cb6.1347023744.git.hans.verkuil@cisco.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 09/07/2012 03:29 PM, Hans Verkuil wrote: > From: Hans Verkuil > > - S/TRY_FMT should always succeed, unless an invalid type field is passed in. > - TRY_FMT should give the same result as S_FMT, all other things being equal. > - ENUMFMT may return different formats for different inputs or outputs. > > This was decided during the 2012 Media Workshop. > > Signed-off-by: Hans Verkuil Reviewed-by: Sylwester Nawrocki A typo managed to snick in below... > --- > Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml | 3 +++ > Documentation/DocBook/media/v4l/vidioc-g-fmt.xml | 9 ++++++--- > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml > index 81ebe48..0bd3324 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-enum-fmt.xml > @@ -58,6 +58,9 @@ structure. Drivers fill the rest of the structure or return an > incrementing by one untilEINVAL is > returned. > > +Note that after switching input or output the list of enumerated image > +formats may be different. > + > > struct<structname>v4l2_fmtdesc</structname> > > diff --git a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > index 52acff1..9ef279a 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > @@ -81,7 +81,7 @@ the application calls theVIDIOC_S_FMT ioctl > with a pointer to av4l2_format structure > the driver checks > and adjusts the parameters against hardware abilities. Drivers > -should not return an error code unless the input is ambiguous, this is > +should not return an error code unless thetype field is invalid, this is > a mechanism to fathom device capabilities and to approach parameters > acceptable for both the application and driver. On success the driver > may program the hardware, allocate resources and generally prepare for > @@ -107,6 +107,10 @@ disabling I/O or possibly time consuming hardware preparations. > Although strongly recommended drivers are not required to implement > this ioctl. > > +The format as returned byVIDIOC_TRY_FMT > +must be identical to whatVIDIOC_S_FMT returns for > +the same input or output. > + >
> struct<structname>v4l2_format</structname> > > @@ -187,8 +191,7 @@ capture and output devices. > EINVAL > > The&v4l2-format;type > -field is invalid, the requested buffer type not supported, or the > -format is not supported with this buffer type. > +field is invalia or the requested buffer type not supported. invalia -> invalid > > > -- Regards, Sylwester