On 3/31/2016 2:50 AM, Michel Dänzer wrote:
> 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.
>
>

Thanks

The patch solved the problem .
Tested-by: Julian Margetson <runaway@candw.ms>

I  would indeed like to see the kernel side fix for the the acceleration 
problem. (Been hoping for it for almost 3 years now)
http://marc.info/?l=dri-devel&m=137881893518240&w=2
I also have Northern Islands cards  and  acceleration with these does 
work with my other powerpc board, an e500v2 .
It also requires the patch in the linked post by Hans Verkuil for Radeon 
NI and SI cards to work .

Regards
Julian