[Mesa-dev] [PATCH] i965: Don't tell the hardware about our UAV access.

[Emil Velikov]

On 26 September 2015 at 21:25, Francisco Jerez <currojerez at riseup.net> wrote:
> Emil Velikov <emil.l.velikov at gmail.com> writes:
>
>> Hi all,
>>
>> On 10 September 2015 at 00:30, Mark Janes <mark.a.janes at intel.com> wrote:
>>> Mark Janes <mark.a.janes at intel.com> writes:
>>>
>>>> Francisco Jerez <currojerez at riseup.net> writes:
>>>>
>>>>> Mark Janes <mark.a.janes at intel.com> writes:
>>>>>
>>>>>> When I tested this, I saw an intermittent BSW gpu hang.  I haven't been
>>>>>> able to confirm that it is due to the host-mem-barrier test.
>>>>>>
>>>>> It would probably be useful to know if the hang is due to any of the
>>>>> image load/store tests or if it's something unrelated.
>>>>
>>>> Yes, you are right.  I will take some time tomorrow to catch the
>>>> specific test.  Given the low rate of gpu hangs on BSW lately, I expect
>>>> it will be due to image load/store tests.  However I need to confirm it.
>>>
>>> I spent time attempting to reproduce hangs with this patch on BSW today.
>>> I forced 3 hangs, but none of them could be attributed to image
>>> load/store tests.
>>>
>> With the above said, should we consider this as inconclusive fix ? If
>> so, what is the plan going forward - is this going to the bin or we'll
>> beat it into shape and merge it ?
>>
> Heh...  The above means that there is an outstanding hang bug on BSW,
> but it's unrelated to the problem addressed by this patch (or
> ARB_shader_image_load_store at any rate).  This patch fixes a GPU hang
> on both BDW and BSW and I recommend it's included in the next stable
> release.
>
I guess I was too subtle here - the patch never landed in master. Not
in its current form at least.

The last related change seem to be commit ac7664e4936(i965/gen7-8:
Poke the 3DSTATE UAV access enable bits.) which is partially reverted
with this patch.

-Emil