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

[Emil Velikov]

On Thu, 8 Nov 2018 at 16:01, Samuel Pitoiset <samuel.pitoiset at gmail.com> wrote:
>
> 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.
>
The patch mentioned should address the GPU hang for radeonsi.
Although eop/eoi <> vs_wave handling is flipped in radv, relative to radeonsi.

If one toggles that, the radeonsi fix could be trivially ported.

HTH
Emil