[PATCH v2] drm/i915: Whitelist SLICE_COMMON_ECO_CHICKEN1 on Geminilake.

[PATCH v2] drm/i915: Whitelist SLICE_COMMON_ECO_CHICKEN1 on Geminilake.

[Kenneth Graunke]

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@whitecape.org>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: stable@vger.kernel.org
---
 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

Re: [PATCH v2] drm/i915: Whitelist SLICE_COMMON_ECO_CHICKEN1 on Geminilake.

[Mark Janes]

Tested-by: Mark Janes <mark.a.janes@intel.com>

Geminilake GPU hangs caused by tesselation tests in VulkanCTS and GLCTS
are fixed by the Mesa patch that toggles this bit.

Kenneth Graunke <kenneth@whitecape.org> 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@whitecape.org>
> Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: stable@vger.kernel.org
> ---
>  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

Re: [PATCH v2] drm/i915: Whitelist SLICE_COMMON_ECO_CHICKEN1 on Geminilake.

[Rodrigo Vivi]

On Fri, Jan 05, 2018 at 08:59:05AM +0000, Kenneth Graunke wrote:
> 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.

I just read the bit definition and fully agree with this.

> 
> v2: Mention WA #0862 in the comment (it doesn't have a name).
> 
> Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
> Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: stable@vger.kernel.org

Merged, thanks.

> ---
>  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
> 

Re: [PATCH v2] drm/i915: Whitelist SLICE_COMMON_ECO_CHICKEN1 on Geminilake.

[Rodrigo Vivi]

On Fri, Jan 05, 2018 at 05:48:35PM +0000, Mark Janes wrote:
> Tested-by: Mark Janes <mark.a.janes@intel.com>

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@whitecape.org> 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@whitecape.org>
> > Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > Cc: stable@vger.kernel.org
> > ---
> >  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