Re: [PATCH 22/24] drm/i915/gen9: Add WaFbcWakeMemOn

[Mika Kuoppala <mika.kuoppala@linux.intel.com>]

Ville Syrjälä <ville.syrjala@linux.intel.com> writes:

> [ text/plain ]
> On Fri, May 27, 2016 at 05:27:02PM +0300, Mika Kuoppala wrote:
>> Set bit 8 in 0x43224 to prevent screen corruption and system
>> hangs on high memory bandwidth conditions. The same wa also suggest
>> setting bit 31 on ARB_CTL. According to another workaround we gain
>> better idle power savings when FBC is enabled.
>> 
>> v2: use correct workaround name
>> 
>> References: HSD#2137218, HSD#2227171, HSD#2136579, BSID#883
>> Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
>> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_reg.h | 2 ++
>>  drivers/gpu/drm/i915/intel_pm.c | 9 +++++++--
>>  2 files changed, 9 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 280d2137f90f..2f3a3960f5f7 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -2208,6 +2208,7 @@ enum skl_disp_power_wells {
>>  #define ILK_DPFC_STATUS		_MMIO(0x43210)
>>  #define ILK_DPFC_FENCE_YOFF	_MMIO(0x43218)
>>  #define ILK_DPFC_CHICKEN	_MMIO(0x43224)
>> +#define   ILK_DPFC_DISABLE_DUMMY0 (1<<8)
>>  #define ILK_FBC_RT_BASE		_MMIO(0x2128)
>>  #define   ILK_FBC_RT_VALID	(1<<0)
>>  #define   SNB_FBC_FRONT_BUFFER	(1<<1)
>> @@ -6053,6 +6054,7 @@ enum skl_disp_power_wells {
>>  #define CHICKEN_PIPESL_1(pipe) _MMIO_PIPE(pipe, _CHICKEN_PIPESL_1_A, _CHICKEN_PIPESL_1_B)
>>  
>>  #define DISP_ARB_CTL	_MMIO(0x45000)
>> +#define  DISP_FBC_MEMORY_WAKE		(1<<31)
>>  #define  DISP_TILE_SURFACE_SWIZZLING	(1<<13)
>>  #define  DISP_FBC_WM_DIS		(1<<15)
>>  #define DISP_ARB_CTL2	_MMIO(0x45004)
>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>> index b2acb82b302b..6d9cf487ea40 100644
>> --- a/drivers/gpu/drm/i915/intel_pm.c
>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>> @@ -70,8 +70,13 @@ static void gen9_init_clock_gating(struct drm_device *dev)
>>  		   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
>>  
>>  	/* WaFbcTurnOffFbcWatermark:skl,bxt,kbl */
>> -	I915_WRITE(DISP_ARB_CTL,
>> -		   I915_READ(DISP_ARB_CTL) | DISP_FBC_WM_DIS);
>> +	/* WaFbcWakeMemOn:skl,bxt,kbl */
>> +	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
>> +		   DISP_FBC_WM_DIS |
>> +		   DISP_FBC_MEMORY_WAKE);
>> +
>> +	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
>> +		   ILK_DPFC_DISABLE_DUMMY0);
>
> I think we might have two partially overlapping w/as here:
> WaFbcWakeMemOn and WaFbcHighMemBwCorruptionAvoidance. Not sure if the
> latter applies to all of KBL. w/a db says all, bspec says a0,b0 only.
>
> Might want to add the other w/a name as well at least. With that this is
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>

I decided to split this for WaFbcNukeOnHostModify
and WaFbcHighMemBwCorruptionAvoidance.

-Mika



>>  }
>>  
>>  static void bxt_init_clock_gating(struct drm_device *dev)
>> -- 
>> 2.5.0
>> 
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>
> -- 
> Ville Syrjälä
> Intel OTC
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