From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Antonino A. Daplas" Subject: Re: 2 more fbcon rotation bugs Date: Mon, 21 Nov 2005 06:04:23 +0800 Message-ID: <4380F2E7.4040101@gmail.com> References: <437DF1EA.7010906@t-online.de> <437E3856.9030509@gmail.com> <437EFA9B.8090402@t-online.de> <437FF1F8.9020307@gmail.com> <43803BD4.7080403@t-online.de> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1EdxKs-00087l-Ny for linux-fbdev-devel@lists.sourceforge.net; Sun, 20 Nov 2005 14:06:58 -0800 Received: from zproxy.gmail.com ([64.233.162.196]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1EdxKs-0004yH-Gk for linux-fbdev-devel@lists.sourceforge.net; Sun, 20 Nov 2005 14:06:58 -0800 Received: by zproxy.gmail.com with SMTP id r28so602670nza for ; Sun, 20 Nov 2005 14:06:58 -0800 (PST) In-Reply-To: <43803BD4.7080403@t-online.de> Sender: linux-fbdev-devel-admin@lists.sourceforge.net Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; charset="iso-8859-1" To: Knut Petersen Cc: linux-fbdev-devel@lists.sourceforge.net Knut Petersen wrote: >=20 >> It seems that cfbfillrect and cfbcopyarea were written in a big-endian >> machine (if I'm not mistaken, by Geert on m68k?) as unaligned access i= n >> little endian produces this bug. >> >> =20 >> > That patch set fixes my problems with vesafb. For the tested subset of > possible > font dimensions and rotation values everything seems to be ok now. But > maybe > someone with a big-endian machine should also verify the code. In big-endian, the original code gets compiled, so there would be no regressions. But does the original code work on them? I don't know yet. >=20 > Isn=B4t it amazing that code as old as this still contains undetected b= ugs? It's quite hard to trigger this bug in an unrotated display because the usual combination of fontwidths and bpp's typically results in 32-bit aligned access. And even if the bug is triggered, it is very difficult to detect as the result will be random pixels at the end of a row of text which the cursor will overwrite eventually anyway. Tony PS: Someone did report before that cfbcopyarea and cfbfillrect does not w= ork correctly at bpp of 24, but I did not look into it then as I was too lazy to create a test :-). ------------------------------------------------------- This SF.Net email is sponsored by the JBoss Inc. Get Certified Today Register for a JBoss Training Course. Free Certification Exam for All Training Attendees Through End of 2005. For more info visit: http://ads.osdn.com/?ad_id=3D7628&alloc_id=3D16845&op=3Dclick