Description of problem:Ran yum update and booted to new kernel kernel-2.6.20-1.2962.fc6. Unable to get better than 800x600, but rebooting back to previous kernel without further change returns the screen to normal resolution. Version-Release number of selected component (if applicable):kernel-2.6.20-1.2962.fc6 and xorg-x11-server-Xvfb.i386 1.1.1-47.10.fc6 How reproducible:Every time Steps to Reproduce: 1. Yum update 2. Re-boot 3. Monitor resolution is 800x600 and no better resolution is possible even if change attempted with system-config-display Actual results:Resolution unable to get to previously set value. If machine is rebooted back to kernel-2.6.20-1.2952.fc6 then screen resolution returns to normal. Expected results: Machine should display normal resolution with new kernel Additional info:Running KDE, and hardware profile is at http://smolt.fedoraproject.org/show?UUID=bd6fa448-485f-4640-b89b-b83c8d8111d3 xorg logs attached.
Created attachment 157891 [details] xorg log with new kernel
Created attachment 157892 [details] xorg log with new kernel - text file
Created attachment 157893 [details] xorg log with old kernel - text file
Created attachment 157894 [details] /var/log/messages
This is probably the cause: -(II) I810(0): VESA VBE DDC read successfully +(II) I810(0): VESA VBE DDC read failed But why it would suddenly stop working, I don't understand. There aren't any kernel patches in there that should have caused this... You should be able to work around this by adding HorizSync 31-80 VertRefresh 56-75 to the "monitor" section of /etc/X11/xorg.conf.
Created attachment 157988 [details] xorg.conf as autogenerated by the system
There was no monitor section in xorg.conf - the xorg.conf file was autogenerated. I have attached the original file at #6. After appending a section containing: Section "Monitor" Identifier "Monitor0" VendorName "Monitor Vendor" ModelName "Monitor Model" HorizSync 31-80 VertRefresh 56-75 EndSection I restarted X with the original kernel running, and this now produced the same problem with no more than 800x600 resolution that I get with the new kernel! Maybe the xorg.conf file needs to have other changes?
I'm not an Xpert but I think it needs to have Monitor "Monitor0" added to the Screen section?
Can we get a copy of boot messages from the old kernel?
Thanks Chuck - I am away from the machine at meetings all today but I will check the xorg.conf details tomorrow and test - and will attach copies of /var/log/messages with relevant lines tomorrow when I am back at the machine. There is no boot.log
I added the Monitor line to xorg.conf, and the machine does boot and gives X with the required resolution. However the normal boot progress screen is blank apart from a message (presumably from the monitor itself) saying that the optimum resolution is 1280x1024 which is what it should choose anyway! Clearly it does not choose the correct resolution until X itself starts. I will soon be installing F7 on this machine and although this seems to be a workaround I am not sure this bug is fully resolved. I hope that once F7 is installed and updated that this problem will not recur on this machine.
I have done a clean f7 install on this machine, and am fully yum updated running kernel 2.6.21-1.3228.fc7 - the problem reported in this bug does not occur with f7 on either the original kernel or the current one. If no-one else reports further after this then I guess this bug should be closed?
There was at least one bug in ~FC6 where the kernel's vm86 call would clobber some registers before returning to userspace, which would confuse X horribly and usually manifest as DDC failing. The offending code appears to be gone in F7, so, hooray.