The Demand Prefetch workaround (binding table prefetching) only applies to Icelake A0/B0. But the Sampler Prefetch workaround needs to be applied to all Gen11 steppings, according to a programming note in the SARCHKMD documentation.
Using the Intel Gallium driver, I have seen intermittent failures in the dEQP-GLES31.functional.copy_image.non_compressed.* tests. After applying this workaround, the tests reliably pass.
BSpec: 9663 Cc: stable@vger.kernel.org Signed-off-by: Kenneth Graunke kenneth@whitecape.org --- drivers/gpu/drm/i915/gt/intel_workarounds.c | 5 +++++ 1 file changed, 5 insertions(+)
(resending with S-o-b added...)
Hi there!
We tried to work around this in the Mesa driver, and managed to do so in i965, anv, iris, but missed doing so in blorp. Oops! I'm planning on fixing that, but setting the SARCHKMD bit to shut off the broken prefetching globally seems like a good idea. That way, we make sure it works for i965, anv, iris, libva, and all the other userspace drivers.
FWIW, I don't have commit access, so I would appreciate it if someone could commit this for me assuming it clears review and testing.
--Ken
diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c index c70445adfb02..a3cb35d058a6 100644 --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c @@ -1254,6 +1254,11 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal) GEN7_SARCHKMD, GEN7_DISABLE_DEMAND_PREFETCH | GEN7_DISABLE_SAMPLER_PREFETCH); + + /* Wa_1606682166:icl */ + wa_write_or(wal, + GEN7_SARCHKMD, + GEN7_DISABLE_SAMPLER_PREFETCH); }
if (IS_GEN_RANGE(i915, 9, 11)) {