On Fri, Jan 05, 2018 at 05:48:35PM +0000, Mark Janes wrote:
> Tested-by: Mark Janes <mark.a.janes@xxxxxxxxx>
Thanks for that and sorry for missing it before merging :(
Also I don't know why patchwork didn't get it automatically.
>
> Geminilake GPU hangs caused by tesselation tests in VulkanCTS and GLCTS
> are fixed by the Mesa patch that toggles this bit.
>
> Kenneth Graunke <kenneth@xxxxxxxxxxxxx> writes:
>
> > Geminilake requires the 3D driver to select whether barriers are
> > intended for compute shaders, or tessellation control shaders, by
> > whacking a "Barrier Mode" bit in SLICE_COMMON_ECO_CHICKEN1 when
> > switching pipelines. Failure to do this properly can result in GPU
> > hangs.
> >
> > Unfortunately, this means it needs to switch mid-batch, so only
> > userspace can properly set it. To facilitate this, the kernel needs
> > to whitelist the register.
> >
> > The workarounds page currently tags this as applying to Broxton only,
> > but that doesn't make sense. The documentation for the register it
> > references says the bit userspace is supposed to toggle only exists on
> > Geminilake. Empirically, the Mesa patch to toggle this bit appears to
> > fix intermittent GPU hangs in tessellation control shader barrier tests
> > on Geminilake; we haven't seen those hangs on Broxton.
> >
> > v2: Mention WA #0862 in the comment (it doesn't have a name).
> >
> > Signed-off-by: Kenneth Graunke <kenneth@xxxxxxxxxxxxx>
> > Acked-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > ---
> > drivers/gpu/drm/i915/i915_reg.h | 2 ++
> > drivers/gpu/drm/i915/intel_engine_cs.c | 5 +++++
> > 2 files changed, 7 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 966e4df9700e..505c605eff98 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -7079,6 +7079,8 @@ enum {
> > #define GEN9_SLICE_COMMON_ECO_CHICKEN0 _MMIO(0x7308)
> > #define DISABLE_PIXEL_MASK_CAMMING (1<<14)
> >
> > +#define GEN9_SLICE_COMMON_ECO_CHICKEN1 _MMIO(0x731c)
> > +
> > #define GEN7_L3SQCREG1 _MMIO(0xB010)
> > #define VLV_B0_WA_L3SQCREG1_VALUE 0x00D30000
> >
> > diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
> > index ebdcbcbacb3c..6bb51a502b8b 100644
> > --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> > +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> > @@ -1338,6 +1338,11 @@ static int glk_init_workarounds(struct intel_engine_cs *engine)
> > if (ret)
> > return ret;
> >
> > + /* WA #0862: Userspace has to set "Barrier Mode" to avoid hangs. */
> > + ret = wa_ring_whitelist_reg(engine, GEN9_SLICE_COMMON_ECO_CHICKEN1);
> > + if (ret)
> > + return ret;
> > +
> > /* WaToEnableHwFixForPushConstHWBug:glk */
> > WA_SET_BIT_MASKED(COMMON_SLICE_CHICKEN2,
> > GEN8_SBE_DISABLE_REPLAY_BUF_OPTIMIZATION);
> > --
> > 2.15.1