Xen + nouveau + modeset = corrupted console

Would it be possible for you to test the latest upstream kernel? It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . If possible, please test the latest v3.2 kernel[1] (Not a kernel in the daily directory). Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag(Only that one tag, please leave the other tags). This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text.

If this bug is fixed by the mainline kernel, please add the following tag 'kernel-fixed-upstream-KERNEL-VERSION'. For example, if kernel version 3.2-rc1 fixed the issue, the tag would be: 'kernel-fixed-upstream-v3.2-rc1'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'. If you believe this bug does not require upstream testing, please add the tag: 'kernel-upstream-testing-not-needed'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

The kernel http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.2.1-precise/linux-image-3.2.1-030201-generic-pae_3.2.1-030201.201201121644_i386.deb is also affected.

simon@xen:~$ uname -a
Linux xen 3.2.1-030201-generic-pae #201201121644 SMP Thu Jan 12 22:01:33 UTC 2012 i686 i686 i386 GNU/Linux
simon@xen:~$ cat /proc/cmdline
placeholder root=/dev/mapper/vg0-root ro

Thank you for taking the time to file a bug report on this issue.

However, given the number of bugs that the Kernel Team receives during any development cycle it is impossible for us to review them all. Therefore, we occasionally resort to using automated bots to request further testing. This is such a request.

We have noted that there is a newer version of the development kernel than the one you last tested when this issue was found. Please test again with the newer kernel and indicate in the bug if this issue still exists or not.

You can update to the latest development kernel by simply running the following commands in a terminal window:

    sudo apt-get update
    sudo apt-get upgrade

If the bug still exists, change the bug status from Incomplete to Confirmed. If the bug no longer exists, change the bug status from Incomplete to Fix Released.

If you want this bot to quit automatically requesting kernel tests, add a tag named: bot-stop-nagging.

 Thank you for your help, we really do appreciate it.

3.2.0-10-generic-pae is also affected

@Simon,

The latest 3.3-rc1 kernel is now available. Could you test this kernel and report if it is also affected by this issue? The 3.3-rc1 kernel is available at:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.3-rc1-precise/

@Joseph, linux-image-3.3.0-030300rc1-generic-pae_3.3.0-030300rc1.201201191835_i386.deb does not fix the problem.

This issue appears to be an upstream bug, since you tested the latest upstream kernel. Would it be possible for you to open an upstream bug report at bugzilla.kernel.org [1]? That will allow the upstream Developers to examine the issue, and may provide a quicker resolution to the bug.

If you are comfortable with opening a bug upstream, It would be great if you can report back the upstream bug number in this bug report. That will allow us to link this bug to the upstream report.

[1] https://wiki.ubuntu.com/Bugs/Upstream/kernel

@Joseph, https://bugzilla.kernel.org/show_bug.cgi?id=27942 mentions similar screen corruption. Could you look at it and tell me if it would be more appropriate to open a separated bug for my problem ? Thanks.

Your card is AGP right? This patchset: https://lkml.org/lkml/2010/12/6/464 fixes it but I haven't gone back to that patch set since I figured nobody uses AGP anymore :-(

@Konrad, thanks, that really looks like you spotted (and fixed) the problem.

I haven't tested your patch as I understand that my AGP card is quite old and I would not want to maintain a patched kernel just to be able to use it with KMS. My Xen box is a P4 and it's quite possible that not many users are still using hardware from that generation. If however, Ubuntu wants to integrate that patch I will happily test it.

@Konrad, thanks for posting the link to the patch.

@Simon, Most folks would ask why the kernel team doesn't just apply the patch and fix it. The reason is that the kernel team is reluctant (not opposed) to apply any patch to a kernel that is not from upstream. Applying patches that don't come from upstream add greatly to the support of the kernel as other upstream patches may touch the same area as the non-upstream patch and may prevent them from applying cleanly.

Joseph, I totally understand the kernel team's position on this. As far
as I'm concerned, this could be marked as "won't fix". Thanks for the
clarification though.

On 12-01-24 03:44 PM, Joseph Salisbury wrote:
> @Simon, Most folks would ask why the kernel team doesn't just apply the
> patch and fix it. The reason is that the kernel team is reluctant (not
> opposed) to apply any patch to a kernel that is not from upstream.
> Applying patches that don't come from upstream add greatly to the
> support of the kernel as other upstream patches may touch the same area
> as the non-upstream patch and may prevent them from applying cleanly.

Konrad, do you know if the patches mentioned in comment #10 will be applied to any of the upstream stable kernels?

Joseph, sorry for the delay - I am somehow not getting email updates on bugs that I've commented on.

So applying the patches requires them to be upstream - and while Dave Airlie had not trouble with them, he did suggest to concentrate on PCIe/PCI subset.

Anyhow, I can dust them off and start respining them for upstream - but the issue I forsee is more of testing. The patches rework the AGP API code and to make sure that it does not impact negatively older platforms I should do due diligence and test them (for regressions). I have some of the AGP chipset motherboards (nvidia, intel, sisworks, and via), but I lack the really weird ones - like SGI ZX1 chipset or the Transmeta boxes. Perhaps if somebody has them laying around I can do this but without that hardware in hand there is a risk..