[Powerpc] Sam460ex Canyonlands issue -Kernel 4.4.6-rc1

[Michel Dänzer]

On 30.03.2016 19:36, Julian Margetson wrote:
> On 3/29/2016 11:49 PM, Michel Dänzer wrote:
>> On 29.03.2016 18:55, Julian Margetson wrote:
>>> On 3/28/2016 11:15 PM, Michel Dänzer wrote:
>>>> On 29.03.2016 08:47, Julian Margetson wrote:
>>>>> Seeing the following when booting kernel 4.6-rc1 on Acube Sam460ex
>>>>> Canyonlands board.
>>>>> This loops for a few times then the kernel boots.
>>>>> No problem with the 4.6-rc1 with an A-eon Tabor Freescale e500v2
>>>>> board.
>>>>>
>>>>> Regards
>>>>>
>>>>> Julian
>>>>>
>>>>>
>>>>>    [    2.197839] ------------[ cut here ]------------
>>>>>    [    2.197850] WARNING: CPU: 0 PID: 1 at
>>>>> drivers/gpu/drm/drm_irq.c:1368 drm_vblank_off+0x2c/0x1e0
>>>> That's
>>>>
>>>>      if (WARN_ON(pipe >= dev->num_crtcs))
>>>>
>>>> My best guess is that drm_vblank_off is called before drm_vblank_init,
>>>> so dev->num_crtcs is still 0.
>>>>
>>>>
>>>> Please provide the full dmesg output corresponding to the problem.
>>>>
>>>>
>>> Attached
>> [...]
>>
>>> [drm] radeon: irq initialized.
>>> [drm:r600_ring_test] *ERROR* radeon: ring 0 test failed
>>> (scratch(0x850C)=0xCAFEDEAD)
>>> radeon 0001:81:00.0: disabling GPU acceleration
>> Okay, so the problem is that acceleration fails to initialize, in which
>> case the driver calls drm_vblank_cleanup.
>>
>> I can see two basic options for a solution: Either don't call
>> radeon_irq_kms_fini/drm_vblank_cleanup if acceleration fails to
>> initialize, or check if acceleration is enabled before calling
>> drm_vblank_on/off. Any preferences?
>>
>>
> Thanks
> 
> No preferences .

Does the attached patch fix the problem?


> I would be interested in a fix for the acceleration problem if possible .

Beware that while the kernel side of this might be relatively easy to
fix, making the userspace radeonsi driver work on big endian hosts would
likely require substantial effort.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer
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