Blank (disconnected) screen during boot with latest 2.6.35-rcX kernels

[Alex Deucher]

On Tue, Jul 20, 2010 at 7:08 AM, trapDoor <trapdoor6 at gmail.com> wrote:
> On Tue, Jul 20, 2010 at 8:09 AM, Alex Deucher <alexdeucher at gmail.com> wrote:
>> On Mon, Jul 19, 2010 at 5:50 PM, trapDoor <trapdoor6 at gmail.com> wrote:
>>> Dear kernel Developers,
>>> I'd like to report a bug occurring on my machine with some of the
>>> latest 2.6.35-rcX and the '-next' kernels. As I'm not sure what is the
>>> problem related to I may have omitted relevant people among the
>>> recipients. If it is so I'll be thankful if someone could cc them.
>>> Also I must apologise for reporting this so late, when it's close to
>>> the end of development cycle for 2.6.35.
>>>
>>> I didn't try to bisect. I've never done it before and maybe someone
>>> will able to reproduce the problem or see straight what's going on by
>>> looking into attached log/config files. But if it is necessary I'll
>>> try my hand at bisecting.
>>>
>>> ******
>>> Description of the problem:
>>>
>>> Affected kernels tested by me: 2.6.35-rc5-git3, 2.6.35-rc4-git5 and
>>> 2.6.35-rc4-next-20100712.
>>> Kernel 2.6.34.1 works OK.
>>>
>>> Briefly what happens is that my graphics card seems to loose
>>> connection with the LCD screen (connected through DVI) during boot.
>>> Initially it does show something - a blank screen with blinking cursor
>>> but it lasts only for about 2-3 seconds and then the screen switches
>>> to stand-by mode giving message 'No signal detected !'. The booting
>>> process seems to continue though, and looking cursorily through
>>> related dmesg and Xorg logs I can't see any suspicious messages
>>> (comparing with the same logs produced when booting from working
>>> kernel). I'm attaching the following files with this e-mail:
>>>    dmesg, Xorg.0.log - produced during successful boot with 2.6.34.1
>>>    dmesg.0, Xorg.0.log.old - these are for the failed boot with 2.6.35-rc5-git3
>>>
>>> Also please find attached config files:
>>>     config-2.6.34.1 - for my current, working kernel
>>>     config-2.6.35-rc5-git3 - based on above, almost all new entries I
>>> left undefined/disabled during making 'oldconfig'; particularly I
>>> didn't touch any options related to PCI, graphics drivers, ACPI or
>>> power management - these should be all the same as in config-2.6.34.1
>>>
>>> All the kernels were compiled on the same PC and system, they have/had
>>> radeon-kms enabled by default and these firmware files compiled in:
>>> R600_rlc.bin, R700_rlc.bin
>>>
>>> ******
>>> A brief specification of my system:
>>>
>>> 1) OS/software:
>>>
>>> Ubuntu 10.04, amd64
>>>
>>> Xorg, xserver, drm, mesa, drm and ati/radeon drivers installed from
>>> the following Ubuntu PPA repository:
>>> https://edge.launchpad.net/~xorg-edgers/+archive/ppa/
>>>
>>> Current versions:
>>> xorg:  1:7.5+6ubuntu1~xorgedgers3~lucid
>>> xserver:  2:1.8.2+git20100705+server-1.8-branch.665aa7ce-0ubuntu0sarvatt2~lucid
>>> xserver-xorg-video-ati:  1:6.13.99+git20100716.cdeb1949-0ubuntu0sarvatt~lucid
>>> xserver-xorg-video-radeon:  1:6.13.99+git20100716.cdeb1949-0ubuntu0sarvatt~lucid
>>> drm:  1:2.4.20+git20100513.a3305b07-0ubuntu0sarvatt~lucid
>>> mesa:  7.9.0+git20100718.4eaf591d-0ubuntu0sarvatt~lucid
>>>
>>> 2) Hardvare:
>>> MB: Asus M4A79T Deluxe with chipsets AMD 790FX/SB750
>>> Processor: AMD Phenom II X4 810
>>> Graphics Card: Asus EAH3650 SILENT/HTDI/512M - based on chipset RV635
>>> PRO, port PCIEx2, connected with LCD through DVI
>>>
>>> ******
>>> Please let me know if anyone requires additional details and if there
>>> is any tracking/testing I could do on my end.
>>
>> The driver is not able to detect any attached monitors with 2.6.35:
>>
>> [    1.980334] No connectors reported connected with modes
>> [    1.980338] [drm] Cannot find any crtc or sizes - going 1024x768
>>
>> [    19.012] (II) RADEON(0): Output HDMI-0 disconnected
>> [    19.012] (II) RADEON(0): Output VGA-0 disconnected
>> [    19.012] (II) RADEON(0): Output DIN disconnected
>> [    19.012] (II) RADEON(0): Output DVI-0 disconnected
>> [    19.012] (WW) RADEON(0): Unable to find connected outputs -
>> setting 1024x768 initial framebuffer
>>
>> I think the attached patch should fix the issue.  if not, can you try
>> reverting b2ea4aa67bfd084834edd070e0a4a47857d6db59 ?
>>
>> Alex
>>
>
> Hi Alex,
> Thanks for looking into this. I feel quite embarrassed that I didn't
> notice those messages from my logs you quoted ..
>
> Your patch (applied to 2.6.35-rc5-git3) has fixed the problem.
> However, Xorg.0.log says now that:
>
> [    17.780] (II) RADEON(0): Output HDMI-0 connected
> [    17.780] (II) RADEON(0): Output VGA-0 disconnected
> [    17.780] (II) RADEON(0): Output DIN disconnected
> [    17.780] (II) RADEON(0): Output DVI-0 disconnected
> [    17.780] (II) RADEON(0): Using exact sizes for initial modes
> [    17.780] (II) RADEON(0): Output HDMI-0 using initial mode 1920x1080
>
> ... but there is no HDMI port in my card. It has 2 DVI's and one Video
> output, that's all.
> The card does support HDMI though, via DVI to HDMI adaptor. But
> currently I've got
> one monitor plugged directly into one of the DVI's - a yellow one,
> where the other port
> is white. There must be a reason that both ports are coloured
> differently. Maybe the
> DVI to HDMI adapter is supported only in the yellow DVI port and
> that's why is recognised
> as HDMI in my system?
>

Probably the oem made two similar boards one with dual DVI and one
with DVI + VGA + HDMI and used the same connector table since the
encoder routing is still correct even if the connectors are named
wrong.  We can add a quirk to fix it.

> Anyway, whether the Xorg log says true or not, it works fine for me,
> no display issues and
> resolution is set correctly. The only problem I see now is a
> noticeable 3D performance
> regression on this kernel (2.6.35-rc5-git3+your-patch) comparing to
> 2.6.34.1. I should make
> some tests, gather details and send that in a separate report soon ..

So the patch fixes the issue?  I'll send it on then.  Looks like your
systems needs a connector table quirk.  Can you send me the pci ids
for your GPU (lspci -vnn) and a copy of your vbios?  To dump your
vbios (as root):

cd /sys/bus/pci/devices/<pci bus id>
echo 1 > rom
cat rom > /tmp/vbios.rom
echo 0 > rom

As to the performance regressions, 2.6.35 added proper support for the
glx vblank stuff, so you are likely seeing apps synchronized to the
vrefresh.

Thanks,

Alex