[Intel-gfx] [PATCH v1 1/2] drm/i915:skl: Add WaEnableGapsTsvCreditFix

[Siluvery, Arun]

On 04/08/2015 09:58, Mika Kuoppala wrote:
> Ben Widawsky <benjamin.widawsky at intel.com> writes:
>
>> On Mon, Aug 03, 2015 at 08:24:56PM +0100, Arun Siluvery wrote:
>>> Cc: Ben Widawsky <benjamin.widawsky at intel.com>
>>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>>> Signed-off-by: Arun Siluvery <arun.siluvery at linux.intel.com>
>>> ---
>>>   drivers/gpu/drm/i915/i915_reg.h | 3 +++
>>>   drivers/gpu/drm/i915/intel_pm.c | 6 ++++++
>>>   2 files changed, 9 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>>> index 77967ca..8991cd5 100644
>>> --- a/drivers/gpu/drm/i915/i915_reg.h
>>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>>> @@ -6849,6 +6849,9 @@ enum skl_disp_power_wells {
>>>   #define GEN7_MISCCPCTL			(0x9424)
>>>   #define   GEN7_DOP_CLOCK_GATE_ENABLE	(1<<0)
>>>
>>> +#define GEN8_GARBCNTL                   0xB004
>>> +#define   GEN9_GAPS_TSV_CREDIT_DISABLE  (1<<7)
>>> +
>>>   /* IVYBRIDGE DPF */
>>>   #define GEN7_L3CDERRST1			0xB008 /* L3CD Error Status 1 */
>>>   #define HSW_L3CDERRST11			0xB208 /* L3CD Error Status register 1 slice 1 */
>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>> index c23cab6..9152113 100644
>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>> @@ -106,6 +106,12 @@ static void skl_init_clock_gating(struct drm_device *dev)
>>>   		/* WaDisableLSQCROPERFforOCL:skl */
>>>   		I915_WRITE(GEN8_L3SQCREG4, I915_READ(GEN8_L3SQCREG4) |
>>>   			   GEN8_LQSC_RO_PERF_DIS);
>>> +
>>> +	/* WaEnableGapsTsvCreditFix:skl */
>>> +	if (IS_SKYLAKE(dev) && (INTEL_REVID(dev) >= SKL_REVID_C0)) {
>>> +		I915_WRITE(GEN8_GARBCNTL, (I915_READ(GEN8_GARBCNTL) |
>>> +					   GEN9_GAPS_TSV_CREDIT_DISABLE));
>>> +	}
>>>   }
>>>
>>>   static void bxt_init_clock_gating(struct drm_device *dev)
>>
>> FWIW, the docs make it sound like BIOS should be doing this. Did you verify we
>> actually don't have the bit set with more recent BKC?
>>
>
> I have pretty recent BIOS and the bit was not set.

I checked about this, it should be done in driver.

regards
Arun

>
>> Tested-by: Ben Widawsky <ben at bwidawsk.net>
>> Reviewed-by: Ben Widawsky <ben at bwidawsk.net>
>>
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90854
> Tested-by: Mika Kuoppala <mika.kuoppala at intel.com>
>
>> --
>> Ben Widawsky, Intel Open Source Technology Center
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>