From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?iso-8859-15?q?Hans-J=FCrgen_Koch?= Subject: Re: [Linux-fbdev-devel] Matrox G550, dual head, 1680x1050 Date: Tue, 6 Mar 2007 10:38:15 +0100 Message-ID: <200703061038.15930.hjk@linutronix.de> References: <200703021053.00955.hjk@linutronix.de> <200703052102.31786.hjk@linutronix.de> <45ED337B.6010209@vc.cvut.cz> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <45ED337B.6010209@vc.cvut.cz> Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: xorg-bounces@lists.freedesktop.org Errors-To: xorg-bounces@lists.freedesktop.org Content-Type: text/plain; charset="iso-8859-1" To: Petr Vandrovec Cc: linux-fbdev-devel@lists.sourceforge.net, xorg@lists.freedesktop.org Am Dienstag, 6. M=E4rz 2007 10:25 schrieb Petr Vandrovec: > Hans-J=FCrgen Koch wrote: > > Am Montag, 5. M=E4rz 2007 05:59 schrieb Petr Vandrovec: > >> Can you try setting vxres for second head from 1680 to 1696, or 1728? > >> Maybe X look at vxres and not at framebuffer line length (what fbset -i > >> reports for line length?) > > > > Here are more details: > > > > 1.) I boot my kernel (vanilla 2.6.20.1) with the following parameters: > > > > video=3Dmatroxfb:outputs:120,pixclock:7380,xres:1680,yres:1050,upper:32, > > lower:4,left:32,right:224,hslen:136,vslen:4,depth:32 > > > > This initializes the primary head correctly. The second head is probably > > wrong, because the monitor's on screen message complains about a > > non-ideal resolution. > > Second head always starts in 640x480/32bpp. You have to use fbset to > switch it to different mode, so matroxfb works fine as far as I can tell. > > > As you can see, the second monitor fell back to VGA resolution, but the > > logs tell that X thinks it successfully switched to 1680x1050. The KDE > > control center reports the same. The image on the second monitor is > > distorted. > > Because X (mga driver) was programming hardware... > > > 4.) I then issue the following command: > > > > $ fbset -fb /dev/fb1 -g 1680 1050 1696 1050 32 -t 7380 224 32 32 4 136 4 > > > > With that, the image on the second monitor immediately becomes clear, a= nd > > I have a fully working xinerama configuration then. > > Yes, and this corrects X programming mistake. > > > As far as I can see, fbset is the only way to initialize the second head > > properly. Neither matroxfb nor mga do it correctly with 1680x1050. > > Well, fbset =3D=3D matroxfb, so I do not quite understand your complaint. > =09 If matroxfb deliberately initializes the second head to 640x480/32bpp, then= it=20 is OK. I thought the kernel boot parameters would apply to both heads. But = on=20 second thought, I agree, it has to be that way. Otherwise you'd run into=20 trouble if you had two different monitors connected as there are no=20 individual settings for both heads. Thanks for your explanations! Hans