From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Date: Mon, 29 Aug 2011 13:34:35 +0000 Subject: Re: [PATCH/RFC v2 1/3] fbdev: Add FOURCC-based format configuration API Message-Id: <201108291534.35951.laurent.pinchart@ideasonboard.com> List-Id: References: <1313746626-23845-1-git-send-email-laurent.pinchart@ideasonboard.com> <201108291455.36145.laurent.pinchart@ideasonboard.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Geert Uytterhoeven Cc: linux-fbdev@vger.kernel.org, linux-media@vger.kernel.org, magnus.damm@gmail.com Hi Geert, On Monday 29 August 2011 15:09:04 Geert Uytterhoeven wrote: > On Mon, Aug 29, 2011 at 14:55, Laurent Pinchart wrote: > >> When will the driver report FB_{TYPE,VISUAL}_FOURCC? > >> - When using a mode that cannot be represented in the legacy way, > >=20 > > Definitely. > >=20 > >> - But what with modes that can be represented? Legacy software cannot > >> handle FB_{TYPE,VISUAL}_FOURCC. > >=20 > > My idea was to use FB_{TYPE,VISUAL}_FOURCC only when the mode is > > configured using the FOURCC API. If FBIOPUT_VSCREENINFO is called with a > > non-FOURCC format, the driver will report non-FOURCC types and visuals. >=20 > Hmm, two use cases: > - The video mode is configured using a FOURCC-aware tool ("fbset on > steroids"). Such as http://git.ideasonboard.org/?p=FBdev-test.git;a=3Dsummary :-) > Later the user runs a legacy application. > =3D> Do not retain FOURCC across opening of /dev/fb*. I know about that problem, but it's not that easy to work around. We have n= o=20 per-open fixed and variable screen info, and FB devices can be opened by=20 multiple applications at the same time. > - Is there an easy way to force FOURCC reporting, so new apps don't have > to support parsing the legacy formats? This is useful for new apps that > want to support (a subset of) FOURCC modes only. Not at the moment. --=20 Regards, Laurent Pinchart