From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vlastimil Babka <vbabka@suse.cz>
Subject: Re: linux-4.4 bisected: kwin5 stuck on kde5 loading screen with
 radeon
Date: Fri, 15 Jan 2016 13:40:36 +0100
Message-ID: <5698E8C4.70207@suse.cz>
References: <5698CB20.9050602@suse.cz> <20160115122629.GC23290@intel.com>
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To: =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= <ville.syrjala@linux.intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>, =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>, Daniel Vetter <daniel.vetter@ffwll.ch>, mgraesslin@kde.org, David Airlie <airlied@linux.ie>, dri-devel@lists.freedesktop.org, LKML <linux-kernel@vger.kernel.org>, Mario Kleiner <mario.kleiner.de@gmail.com>, kwin@kde.org
List-Id: dri-devel@lists.freedesktop.org

On 01/15/2016 01:26 PM, Ville Syrj=E4l=E4 wrote:
> On Fri, Jan 15, 2016 at 11:34:08AM +0100, Vlastimil Babka wrote:
>>
>> I have suspected that kwin is waiting for some event, but neverthele=
ss
>> tried bisecting the kernel between 4.3 and 4.4, which lead to:
>>
>> # first bad commit: [4dfd64862ff852df7b1198d667dda778715ee88f] drm: =
Use
>> vblank timestamps to guesstimate how many vblanks were missed
>>
>> I can confirm that 4.4 works if I revert the following commits:
>> 63154ff230fc9255cc507af6277cd181943c50a1 "drm/amdgpu: Fixup hw vblan=
k
>> counter/ts for new drm_update_vblank_count() (v3)"
>>
>> d1145ad1e41b6c33758a856163198cb53bb96a50 "drm/radeon: Fixup hw vblan=
k
>> counter/ts for new drm_update_vblank_count() (v2)"
>
> The sha1s don't seem to match what I have, so not sure which kernel t=
ree

Hm sorry, I pasted the sha1 of the reverts by mistake.
Correct sha1 are:
5b5561b3660db734652fbd02b4b6cbe00434d96b "drm/radeon: Fixup hw vblank=20
counter/ts for new drm_update_vblank_count() (v2)"
fa4270d8e0257b4b76f11baa2866f4313d29aaf5 "drm: Don't zero vblank=20
timestamps from the irq handler"
235fabe09b46469adad2c9e4cb0563758155187c "drm: Add DRM_DEBUG_VBL()"
4dfd64862ff852df7b1198d667dda778715ee88f "drm: Use vblank timestamps to=
=20
guesstimate how many vblanks were missed"
8e36f9d33c134d5c6448ad65b423a9fd94e045cf "drm/amdgpu: Fixup hw vblank=20
counter/ts for new drm_update_vblank_count() (v3)"

Also, it turns out that the process actually showing the progress is
"ksplashqml", not kwin. It survives killing kwin, and restarting kwin
just makes it shown on top again, or something. If I force kill
ksplashqml instead of kwin, the desktop works including decorations
and everything. ksplashqml itself also waits in kernel in poll().

I'll try some of your suggestions, thanks!