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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140424133652.GA19610@amd.pavel.ucw.cz>
Date:	Thu, 24 Apr 2014 15:36:52 +0200
From:	Pavel Machek <pavel@....cz>
To:	Daniel Vetter <daniel.vetter@...ll.ch>
Cc:	Chris Wilson <chris@...is-wilson.co.uk>,
	intel-gfx <intel-gfx@...ts.freedesktop.org>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	dri-devel <dri-devel@...ts.freedesktop.org>,
	kernel list <linux-kernel@...r.kernel.org>,
	Jiri Kosina <jikos@...os.cz>
Subject: Re: 3.15-rc2: i915 regression: only top 20% of screen works in X

On Thu 2014-04-24 08:03:04, Daniel Vetter wrote:
> On Thu, Apr 24, 2014 at 7:50 AM, Chris Wilson <chris@...is-wilson.co.uk> wrote:
> > 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
> >
> > 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.
> 
> Oh right, g4x going beserk :( Apparently something changed in 3.15
> somewhere which made this much more likely, but like Chris said in
> Jiri's case it's too unreliable to reproduce for a bisect. We've had
> this come&go pretty much ever since kms support was merged and never
> tracked it down.

So far I went back to 3.14, and yes, graphics works there.

Back to 3.15, put it to smaller monitor. This time, top 30% of screen
works, and last working scanline is copied to the rest 60% of
screen. [With the exception of mouse cursor, that somehow affects that
magically.]

> The bug is https://bugs.freedesktop.org/show_bug.cgi?id=76554
> 
> Like Chris said please test latest drm-intel-nighlty from
> http://cgit.freedesktop.org/drm-intel to make sure that the recently
> merged mitigation measures work properly. But those won't get your gpu
> back, only the display and it's only for 3.16. We're still hunting a
> proper fix for 3.15.

So you know where the bug is or not?

> And if you can indeed reliably reproduce this a bisect could be really useful.

I'm confused. And yes, it seems reliable. But I'm not sure if I see
same bug you are talking about.
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/