From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40684) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X6bd6-0006sr-SZ for qemu-devel@nongnu.org; Mon, 14 Jul 2014 04:29:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X6bd0-000084-2q for qemu-devel@nongnu.org; Mon, 14 Jul 2014 04:29:00 -0400 Received: from ssl.dlhnet.de ([82.141.21.42]:45588) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X6bcz-00007O-T3 for qemu-devel@nongnu.org; Mon, 14 Jul 2014 04:28:54 -0400 Message-ID: <53C394C2.40707@dlhnet.de> Date: Mon, 14 Jul 2014 10:28:50 +0200 From: Peter Lieven MIME-Version: 1.0 References: <1405074278-16230-1-git-send-email-kraxel@redhat.com> <1405074278-16230-4-git-send-email-kraxel@redhat.com> <53C385BA.4090601@dlhnet.de> <1405322943.9343.28.camel@pasglop> In-Reply-To: <1405322943.9343.28.camel@pasglop> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PULL 3/3] cirrus: Fix host CPU blits List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Benjamin Herrenschmidt Cc: Gerd Hoffmann , qemu-devel@nongnu.org On 14.07.2014 09:29, Benjamin Herrenschmidt wrote: > On Mon, 2014-07-14 at 09:24 +0200, Peter Lieven wrote: >> it seems you have digged into the cirrus code recently. Have you an idea how to >> fix the issue with the graphics corruption for cirrus vga and recent X Server versions? >> >> E.g. take an Ubuntu 14.04 Desktop CD, boot it into live mode and open terminal. >> >> I have tried to debug it a little, but I have no clue how to solve this. I tried to get >> hands on a real hardware Cirrus Logic Graphics card and test if this happens there as well, >> but I had no chance to get one. > I *think* it is a X server side bug. They broke 24bpp packed pixel > format. I've seen patches submitted to the Xorg list fairly recently by > somebody from canonical. > > You can test by creating an xorg.conf to force the display to 16bpp > instead of 24 and see if that helps. Will do, thanks for the pointer. Do you see a way to work around this in the graphics driver. E.g. blacklisting 24bpp modes etc. Even if X.Org people actually merge the fixes there are 2 years of Linux releases out there that have corrupted graphics. Peter