[Mesa-stable] [PATCH] radv: adjust the VGT workaround for prim restart on GFX9

[Samuel Pitoiset]

On 11/8/18 4:43 PM, Emil Velikov wrote:
> HI guys,
> 
> On Tue, 16 Oct 2018 at 22:06, Marek Olšák <maraeo at gmail.com> wrote:
>>
>> On Thu, Oct 11, 2018 at 4:43 AM Samuel Pitoiset
>> <samuel.pitoiset at gmail.com> wrote:
>>>
>>> WD_SWITCH_ON_EOP seems to be the only workaround that fixes
>>> the GPU hangs with Yakuza and The Evil Within on Vega. I don't
>>> like as it might decrease geometry performance as pointed out
>>> by Marek, but I don't know how to implement a better one.
>>>
>>> Cc: mesa-stable at lists.freedesktop.org
>>> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
>>> ---
>>>   src/amd/vulkan/radv_pipeline.c | 13 +++++++++++--
>>>   1 file changed, 11 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/amd/vulkan/radv_pipeline.c b/src/amd/vulkan/radv_pipeline.c
>>> index 426b417e172..2256b2c58e9 100644
>>> --- a/src/amd/vulkan/radv_pipeline.c
>>> +++ b/src/amd/vulkan/radv_pipeline.c
>>> @@ -3412,14 +3412,23 @@ radv_compute_ia_multi_vgt_param_helpers(struct radv_pipeline *pipeline,
>>>          }
>>>
>>>          /* Workaround for a VGT hang when strip primitive types are used with
>>> -        * primitive restart.
>>> +        * primitive restart. This fixes GPU hangs with Yakuza and The Evil
>>> +        * Within, at least. Not sure if we can implement a better workaround.
>>>           */
>>>          if (pipeline->graphics.prim_restart_enable &&
>>>              (prim == V_008958_DI_PT_LINESTRIP ||
>>>               prim == V_008958_DI_PT_TRISTRIP ||
>>>               prim == V_008958_DI_PT_LINESTRIP_ADJ ||
>>>               prim == V_008958_DI_PT_TRISTRIP_ADJ)) {
>>
>> Adjacency primitive types should already have wd_switch_on_eop set to true.
>>
>> The workaround I'm going to use is:
>>
>>          if (!wd_switch_on_eop && key->u.primitive_restart)
>>              partial_vs_wave = true;
>>
>> Our docs say we should do this. I don't know why it still hangs with
>> this workaround.
>>
> I can see that Marek committed the above suggestion to radeonsi as
> commit eae8f49fc65e6e625f5e05d38c3bf1b61b84bd3d
> Yet I cannot see an equivalent patch for radv.
> 
> Samuel I'm assuming that you're working on something else and didn't
> get back to this one?
> Alternatively, please let me know which commit addresses the GPU
> hangs, and if we'd want it in stable.

Hi,

"[PATCH v2] radv: add a workaround for a VGT hang with prim restart and 
strips" should already be in stable.

This one hasn't been pushed because it might decrease performance and we 
might want to find a better solution.

Thanks.
> 
> Thanks
> Emil
>