Subject: Re: [BUG][REGRESSION] mangled display since -rc1
To: Thorsten Leemhuis <regressions@leemhuis.info>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Joerg Roedel <jroedel@suse.de>
References: <da26da99edcd68c05ef63a28749eff37@posteo.de>
 <5d11d88ae7d77ce1c0adbc9e6ffc7633@posteo.de> <20161031152136.GA3473@suse.de>
 <6e267e2b-ddd2-8768-8fb5-72a1781c4cc1@posteo.de>
 <20161031215454.GB3473@suse.de>
 <79A6D00F-A07B-49B8-84D6-FB80E9D181FB@posteo.de> <87k2cnjuan.fsf@intel.com>
 <27a0c8f9-0f1f-fa99-fc96-6c6fcba4bfe4@leemhuis.info>
Cc: Linux kernel <linux-kernel@vger.kernel.org>,
        torvalds@linux-foundation.org, daniel.vetter@intel.com
From: Martin Kepplinger <martink@posteo.de>
Message-ID: <0f63c442-29c0-bcf7-2f0b-a2733eb7794b@posteo.de>
Date: Sun, 6 Nov 2016 12:43:22 +0100
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Am 2016-11-06 um 12:21 schrieb Thorsten Leemhuis:
> On 01.11.2016 12:47, Jani Nikula wrote:
>> On Tue, 01 Nov 2016, Martin Kepplinger <martink@posteo.de> wrote:
>>> I'll come up with a nouveau system example and it was quite easy to bisect. To quote the merge commit msg:
>>> This also required some changes outside of the IOMMU code, but these are acked by the respective maintainers.
>>> Any help on bisecting into it would be awesome.
>> So the information here is pretty scarce. Please file a bug at [1],
>> describe the problem, perhaps add drm.debug=14 module parameter and
>> attach dmesg from boot to reproducing the problem.
> 
> Martin, did you do that and can point me to the bug? And if not: Any
> news on the issue?
> 
> FWIW: I added this report to the list of regressions for Linux 4.9. I'll
> watch this thread for further updates on this issue to document progress
> in my weekly reports. Please let me know via regressions@leemhuis.info
> in case the discussion moves to a different place (bugzilla or another
> mail thread for example).
> 
> tia! Ciao, Thorsten
> 

I did not file a bug in bugzilla yet. I haven't given up that we can fix
this here before the release. I've ignored it the last few days though.

Again: This is the first bad commit:

[56e520c7a0a490b63b042b047ec9659fc08762a4] Merge tag
'iommu-updates-v4.9' of
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

If you know how to bisect into this, please share your thoughts. Linus'
merge here is bigger than iommu-update-v4.9 i think and that's what I
have to look at really. I'm not sure how though.

One part of the merge is indeed iiommu-updates-v4.9:

That's the tag:
https://git.kernel.org/cgit/linux/kernel/git/joro/iommu.git/tag/?h=iommu-updates-v4.9

and the tagged object:
https://git.kernel.org/cgit/linux/kernel/git/joro/iommu.git/commit/?h=iommu-updates-v4.9&id=13a08259187c5cd3f63d98efa159ab42976d85a4

I'll have to think about how to check the iommu-updates-v4.9 part of the
merge again... to eliminate something.