From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Koller Subject: Re: [Linux-fbdev-devel] [PATCH 1/2] fb: add support for foreign endianness Date: Tue, 19 Feb 2008 00:35:08 +0100 Message-ID: <47BA162C.5000807@anagramm.de> References: <20080205154432.GA8749@localhost.localdomain> <20080214224942.a0cb6218.akpm@linux-foundation.org> <20080215164542.GB16810@localhost.localdomain> <20080218081847.e9e65f2f.krzysztof.h1@poczta.fm> <19805.1203355811@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <19805.1203355811@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: linux-fbdev-devel@lists.sourceforge.net Cc: Krzysztof Helt , adaplas@gmail.com, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Geert Uytterhoeven , Andrew Morton , avorontsov@ru.mvista.com Valdis.Kletnieks@vt.edu schrieb: > On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said: >> I know two fb drivers which use endianess information (pm2fb and s3c2410fb). >> Both resolve endianess at driver level. Actually, both handle it by setting special >> bits so the graphics chip itself reorder bytes to transform foreign endianess. >> I understand that this patch is for chips which cannot reorder bytes by themselves. > > Does anybody know of such a chip that's actually available in the wild? Or are > we writing drivers for speculative possible chips? > I had troubles with the Silicon Motion SM501/SM502 endianess on PowerPC PCI vs. LocalBus. The chip also has a register to swap endianess, but that seems to only affect some LocalBus modes. The current fb and X drivers are working, but when it comes to font aliasing and hw-acceleration, the problems start to rise again... Regards, Clemens