Re: Screen corruption and crash at boot with Xen 4.1.0 & linux 2.6.39 on some systems

[Anthony Wright <anthony@overnetdata.com>]

Hi Konrad,

Sorry to ask the same question again, but does 2.6.39.1 include the
patches from stable/2.6.39.x  that fixed this problem?

thanks,

Anthony.
[I've cc'd xen-devel as I think I hit reply rather than reply-all a
little while back]

On 07/06/2011 15:52, Konrad Rzeszutek Wilk wrote:
> On Tue, Jun 07, 2011 at 12:42:27PM +0100, Anthony Wright wrote:
>> I ran with the stable/2.6.39.x version and that's fixed the problem
>> (didn't need to do the revert).
>>
>> The first build failed because mm/swapfile.c had an undefined reference
>> to frontswap_init and by default FRONTSWAP is not set.
> <nods>That is fixed now.
>> Are these patches in mainline 2.6.39.1 or will I have to wait for 3.0.0 ?
> No. The VGA support one might show up in 3.0 depending on Linus. I sent an
> email asking him to pull it: https://lkml.org/lkml/2011/6/6/391
> but it could be considered a feature and the merge window for features elapsed :-(
>
> It could also be considered a bug ...  anyhow leaving it up to Linus
> and I would recommend you use 2.6.39.1 and I can respond to this email thread
> whether Linus has pulled the patch or not.
>
>> thanks,
>>
>> Anthony
>>
>> On 02/06/2011 15:51, Konrad Rzeszutek Wilk wrote:
>>> On Thu, Jun 02, 2011 at 02:08:03PM +0100, Anthony Wright wrote:
>>>> I have a custom built system based on LFS 6.6 with xen 4.1.0 & linux 2.6.39 built from source. The system boots correctly on one system (after a problem with the USB disk has been worked around), however when I try to boot the same system on another machine the screen corrupts shortly after handover from the bootloader. This happens on 2 out of the 3 machines I have tried it on.
>>>>
>>>> I was originally using xen 4.1.0 & linux 2.6.38.7, and with this combination the bootloader would work correctly, xen would work correctly and it would crash and the screen corrupt on the handover from xen to linux. I had a hunt around and found http://wiki.xensource.com/xenwiki/XenPVOPSDRM which talks about the graphics subsystem and says "What is boils down to is: if you want to use a stock kernel from ftp.kernel.org wait till 2.6.39 gets released". As a result I have switched to xen 4.1.0 & linux 2.6.39 but get the same result.
>>> We missed a couple of patches and had to revert some.
>>>> The motherboard is a Gigabit GA-MA69VM-S2.
>>>>
>>>> The lspci -vvv output is attached.
>>>>
>>>> What I did notice is the way the screen resolution changes during boot is different for the two main machines that I test on. On the machine that works, instead of the 80x25 console that I'm used to with xen 3.4.1, I get a much higher resolution output with two penguins at the top with 4.1.0. When I boot the system without the xen hypervisor linux starts at the 80x25 resolution but then quickly puts the screen into high resolution. On the machine that fails, when I boot the system without the xen hypervisor, linux starts at 80x25 resolution, appears to do a resolution change (whole screen flickers) a few seconds later but leaves the resolution at 80x25.
>>>>
>>>> Am I doing something wrong? Is this a bug? Is there a workaround? Should I try a different kernel version?
>>> Try git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/2.6.39.x
>>>
>>> and if that does not work, on top of that branch, also try reverting these two patches:
>>>
>>> 03a80665341bbb9a57064c2ddeca13b554d56893
>>> ("drm/radeon/nouveau: fix build regression on alpha due to Xen changes.)
>>> and 
>>> d87dfdbfc91c5e37288e7e8f7afdd992ba61a60d.
>>> ("Revert "ttm: Utilize the DMA API for pages that have TTM_PAGE_FLAG_DMA32 set.")
>>>
>>>> I'm happy to live with the 80x25 resolution screen but none of the screen resolution options that I've tried have had any effect.
>>>>
>>>> Thanks,
>>>>
>>>> Anthony.
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