[Intel-gfx] linux-3.9: [drm:intel_dp_aux_wait_done] *ERROR* dp aux hw did not signal timeout (has irq: 1)!

Daniel Vetter daniel.vetter at ffwll.ch
Wed May 1 11:33:46 CEST 2013

Aside: Please always cc relevant mailing lists when reporting issues.

On Wed, May 1, 2013 at 12:39 AM, Sedat Dilek <sedat.dilek at gmail.com> wrote:
> On Wed, May 1, 2013 at 12:30 AM, Martin Mokrejs
> <mmokrejs at fold.natur.cuni.cz> wrote:
>> Hi Sedat, [+Imre and +Daniel who were in the original thread]
>> Sedat Dilek wrote:
>>> On Tue, Apr 30, 2013 at 11:56 PM, Martin Mokrejs
>>> <mmokrejs at fold.natur.cuni.cz> wrote:
>>>> Hi,
>>>>   I found the above error in my dmesg and found a thread
>>>> https://lkml.org/lkml/2013/2/27/275 . However, I am not sure this
>>>> is really my hardware BIOS bug or a kernel bug. Would you please
>>>> ensure me I should blame Dell for this Dell Vostro 3550 laptop?
>>>> This is a Sandy Bridge-based laptop with no extra graphics chip,
>>>> has only the intel VGA bundled into my core i7 CPU.
>>>> I am attaching a full dmesg from my system.
>>>>   Regarding symptoms ... I think at the time I got this error
>>>> message in dmesg I had my external HDMI1 screen working ... but I
>>>> admit I have in general "random" issues that my external HDMI1 display
>>>> is not detected during bootup and stays blank. xrandr says HDMI1 is
>>>> disconnected I cannot make it to enable HDMI1 for me. Turning on/off
>>>> the LCD itself does not work, also not manually setting its input to
>>>> HDMI (it has also VGA D-SUB input socket). But these issue exist in
>>>> 3.7/3.8 series as well. So maybe this ERROR message which landed in
>>>> 3.9-rc1 is good for me. To date, have the latest BIOS, A11 for this
>>>> model.
>>> IIRC that was fixed with [1] and is included in Linux-v3.9?
>> Seems not. This is vanilla 3.9.
> I am on Linux-Next, try that or drm-intel-next?

Hm, random HDMI failures combined with the dp aux stuff being stuck
makes some sense. If drm-intel-nightly or linux-next don't cut it for
you, please file a bug report on bugs.freedesktop.org against DRI ->

>>> Might be good to CC intel-gfx ML.
>> Yeah, I wanted to ask first ... and due to the size of dmesg it would not
>> likely pass filters anyway ... Please Cc: the list for the sake of internet
>> archives if you find this *relevant*. I just do not know whether this is
>> a false alarm or not. Sorry for me being so suspicious. ;-)
>>> AFAICS I have seen some /similiar/same) drm/kms/i915 warnings/errors
>>> with v3.9-rc7+ Ubuntu/raring mainline kernels [1].
>>> But I might be wrong...
>> OK, I did another cold boot and this time the ERROR message is gone, but the
>> line with Wrong MCH_SSKPD stays. Below are both snippets of two plain 3.9 bootups.
> That one I reported, too.
> Daniel was reflecting on it, can't say if he made a decision.
> AFAICS harmless.

Worst case it can cause underruns, which especially on DP can cause
loss of sync and black screen.

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