From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paulo Marques Subject: Re: [PATCH] pxafb: Add support for other palette formats Date: Tue, 03 Jul 2007 18:21:38 +0100 Message-ID: <468A85A2.1070506@grupopie.com> References: <200707031607.08511.hjk@linutronix.de> <18058.28725.106989.860166@ipc1.karo> <468A7359.5010305@grupopie.com> <200707031845.57256.hjk@linutronix.de> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200707031845.57256.hjk@linutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.arm.linux.org.uk Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org+linux-arm-kernel=m.gmane.org@lists.arm.linux.org.uk Content-Type: text/plain; charset="iso-8859-1"; format="flowed" To: =?ISO-8859-1?Q?Hans-J=FCrgen_Koch?= Cc: Thomas Gleixner , linux-fbdev-devel@lists.sourceforge.net, linux-arm-kernel@lists.arm.linux.org.uk Hans-J=FCrgen Koch wrote: > Am Dienstag 03 Juli 2007 18:03 schrieb Paulo Marques: >> [...] >> Or maybe teach fbcon to use 18bpp modes? >=20 > This would only make sense if this is a common format that other > chips use, too. I don't see this as a good reason not to implement 18bpp support in=20 fbcon. "Just PXA270 18bpp devices" can be a lot of devices out there. Anyway, can fbcon work with 18bpp palette mode? If it does, then this=20 should be enough for most users of 18bpp pxafb users: have a console=20 with a palette mode and then switch to non-palette mode and run whatever=20 windowing system supports 18bpp. I guess that even if it doesn't support 18bpp palette mode now, it=20 shouldn't be that hard to implement (nor should it cause that much bloat=20 to fbcon). >>> BTW: PXA255 doesn't have an LCCR4 register. >> If we make sure that we don't touch LCCR4 registers unless the platform = >> driver asks for 18bpp we should be in the clear, no? >> >> However, the current patch does write to LCCR4 without checking this,=20 >> but this should be a no-op if there is no register there, AFAICS. >=20 > Arrg, no, you can't do this. Even if it works on your current PXA255 > revision, writing to a nonexistent register is certainly not something > we should do in a proper driver. Yes, I wasn't proposing that this be kept (that would be waaay too=20 ugly), only pointing out that it shouldn't crash existing setups. >> I'll try to handle it more correctly in my next patch, anyway. >=20 > So will I. I'll update my patch. Ok. --=20 Paulo Marques - www.grupopie.com "God is real, unless declared integer." ------------------------------------------------------------------- List admin: http://lists.arm.linux.org.uk/mailman/listinfo/linux-arm-kernel FAQ: http://www.arm.linux.org.uk/mailinglists/faq.php Etiquette: http://www.arm.linux.org.uk/mailinglists/etiquette.php