From: Stefan Richter <stefanr@s5r6.in-berlin.de>
To: "Zanoni, Paulo R" <paulo.r.zanoni@intel.com>
Cc: "airlied@redhat.com" <airlied@redhat.com>,
"intel-gfx@lists.freedesktop.org"
<intel-gfx@lists.freedesktop.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
"Vetter, Daniel" <daniel.vetter@intel.com>
Subject: Re: Regression of v4.6-rc vs. v4.5 bisected: a98ee79317b4 "drm/i915/fbc: enable FBC by default on HSW and BDW"
Date: Fri, 6 May 2016 00:54:57 +0200 [thread overview]
Message-ID: <20160506005457.1fa4b4e3@kant> (raw)
In-Reply-To: <1462474211.29701.21.camel@intel.com>
On May 05 Zanoni, Paulo R wrote:
> Em Qui, 2016-05-05 às 19:45 +0200, Stefan Richter escreveu:
> > Oh, and in case you - the person reading this commit message - found
> > this commit through git bisect, please do the following:
> > - Check your dmesg and see if there are error messages mentioning
> > underruns around the time your problem started happening.
> >
> > Well, I always had the followings lines in dmesg:
> > [drm:intel_set_cpu_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A
> > [drm:intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun
>
> Oh, well... I had a patch that would just disable FBC in case we saw a
> FIFO underrun, but it was rejected. Maybe this is the time to think
> about it again? Otherwise, I can't think of much besides disabling FBC
> on HSW until all the underruns and watermarks regressions are fixed
> forever.
Just to be clear though, I know that these messages are emitted when the
monitor is switched on, and when sddm is being shut down --- but I do not
know whether there is any sort of underrun when I get the FBC related
freeze (since I just don't get any kernel messages at that point).
Is there a chance that a serial console would fare better than
netconsole? This board and another PC in its vicinity have got onboard
serial ports but I don't have cables at the moment.
> > - Download intel-gpu-tools, compile it, and run:
> > $ sudo ./tests/kms_frontbuffer_tracking --run-subtest '*fbc-*' 2>&1 | tee fbc.txt
> > Then send us the fbc.txt file, especially if you get a failure.
> > This will really maximize your chances of getting the bug fixed
> > quickly.
> >
> > Do you need this while FBC is enabled, or can I run it while FBC is
> > disabled?
>
> FBC enabled. Considering your description, my hope is that maybe some
> specific subtest will be able to hang your machine, so testing this
> again will require only running the specific subtest instead of waiting
> 18 hours.
The kms_frontbuffer_tracking runs from which I posted output two hours
ago did not trigger a lockup.
(I ran them while X11 was shut down because otherwise
kms_frontbuffer_tracking would skip all tests with "Can't become DRM
master, please check if no other DRM client is running.")
> > PS:
> > I am mentioning the following just in case that it has any relationship
> > with the FBC related kernel freezes. Maybe it doesn't... There is
> > another recent regression on this PC, but I have not yet figured out
> > whether it was introduced by any particular kernel version. The
> > regression is: When switching from X11 to text console by [Ctrl][Alt][Fx]
> > or by shutting down sddm, I often only get a blank screen. I suspect
> > that this regression was introduced when I replaced kdm by sddm, but
> > I am not sure about that.
>
> Maybe there is some relationship, since this operation involves a mode
> change. You can also try checking dmesg to see if there are underruns
> right when you do the change.
Yes, this is accompanied by
[drm:intel_set_cpu_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A
[drm:intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun
--
Stefan Richter
-======----- -=-= --=-=
http://arcgraph.de/sr/
next prev parent reply other threads:[~2016-05-05 22:55 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-26 19:00 Regression of v4.6-rc vs. v4.5: hangs after a few minutes after boot Stefan Richter
2016-04-26 19:05 ` Stefan Richter
2016-04-26 19:07 ` Stefan Richter
2016-04-27 18:51 ` Stefan Richter
2016-04-27 19:22 ` Stefan Richter
2016-04-27 19:37 ` Stefan Richter
2016-04-29 8:07 ` Stefan Richter
2016-04-30 13:51 ` Regression of v4.6-rc vs. v4.5: Merge tag 'drm-intel-next-2016-02-29' Stefan Richter
2016-05-05 17:45 ` Regression of v4.6-rc vs. v4.5 bisected: a98ee79317b4 "drm/i915/fbc: enable FBC by default on HSW and BDW" Stefan Richter
2016-05-05 18:50 ` Zanoni, Paulo R
2016-05-05 19:59 ` [Intel-gfx] " Daniel Vetter
2016-05-05 22:56 ` Stefan Richter
2016-05-05 22:54 ` Stefan Richter [this message]
2016-05-05 23:55 ` Zanoni, Paulo R
2016-05-08 10:18 ` Stefan Richter
2016-05-08 11:20 ` Stefan Richter
2016-05-05 19:54 ` Stefan Richter
2016-05-05 20:45 ` Stefan Richter
2016-05-06 6:37 ` Daniel Vetter
2016-05-08 11:44 ` Stefan Richter
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