3.15-rc2: i915 regression: only top 20% of screen works in X

[Pavel Machek]

Hi!

> > > > After update to 3.15-rc2, only top 20% of screen works on X.
> > > >
> > > > 00:02.0 VGA compatible controller: Intel Corporation 4 Series Chipset
> > > > Integrated Graphics Controller (rev 03)
> > > >
> > > > 00:02.1 Display controller: Intel Corporation 4 Series Chipset
> > > > Integrated Graphics Controller (rev 03)
> > > >            Subsystem: Intel Corporation Device d614
> > > >            Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop-
> > > >            ParErr- Stepping- SERR- FastB2B- DisINTx-
> > > >            Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast
> > > >            >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
> > > >            Latency: 0
> > > >            Region 0: Memory at d0400000 (64-bit, non-prefetchable)
> > > >            [size=1M]
> > > >            Capabilities: <access denied>
> > > >
> > > > This worked before. I believe it worked in 3.14. It definitely works
> > > > in 3.11-rc2.
> > > 
> > > Screenshot or more detailed description of what "only top 20% of
> > > screen works in X" means?
> > > Anything in dmesg?
> > 
> > Actually yes, dmesg suggests it is quite
> > sick. drivers/gpu/drm/drm_mm.c:767 warning triggered
> > repeatedly. Also.. initial framebuffer does not work ; I don't seem to
> > see anything before X start up. (This is Debian 6.0.9)
> 
> That says that i915.ko failed to initialise the GPU (or rather the GPU
> wasn't responding) and bailed during module load. The key line here is

> [drm:init_ring_common] *ERROR* render ring initialization failed ctl
> 0001f001 head 00002034 tail 00000000 start 0012f000

Actually, I'm not using modules -- everything is build-in. Can you try
that config? Perhaps you can then reproduce the failure.

> Jiri has been seeing a similar issue creep in during resume, but it is
> not reliable enough to bisect. Is your boot failure reliable enough to
> bisect? Also drm-intel-nightly should mitigate this failure and allow
> i915.ko to continue to load and run X, which would be worth testing to
> make sure that works as intended.

So far it failed 100% of time, but this is my main machine, so
bringing it down for extended periods is no-no.

Greetings to Prague :-). Jiri, do you have  i915 a module or build-in?

Best regards,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
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