[Intel-gfx] [PATCH 15/49] drm/i915/bxt: add GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ workaround

[Nick Hoath]

On 08/04/2015 14:10, Deak, Imre wrote:
> On ke, 2015-04-08 at 14:04 +0100, Nick Hoath wrote:
>> On 17/03/2015 09:39, Imre Deak wrote:
>>> From: Ben Widawsky <benjamin.widawsky at intel.com>
>>>
>>> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
>>> Signed-off-by: Imre Deak <imre.deak at intel.com>
>>> ---
>>>    drivers/gpu/drm/i915/i915_reg.h | 1 +
>>>    drivers/gpu/drm/i915/intel_pm.c | 4 +++-
>>>    2 files changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>>> index 3369a11..b7ba061 100644
>>> --- a/drivers/gpu/drm/i915/i915_reg.h
>>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>>> @@ -6104,6 +6104,7 @@ enum skl_disp_power_wells {
>>>    #define GEN8_UCGCTL6				0x9430
>>>    #define   GEN8_GAPSUNIT_CLOCK_GATE_DISABLE	(1<<24)
>>>    #define   GEN8_SDEUNIT_CLOCK_GATE_DISABLE	(1<<14)
>>> +#define   GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ (1<<28)
>>>
>>>    #define GEN6_GFXPAUSE				0xA000
>>>    #define GEN6_RPNSWREQ				0xA008
>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>> index d5dd0b3..52d3c02 100644
>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>> @@ -103,10 +103,12 @@ static void bxt_init_clock_gating(struct drm_device *dev)
>>>    	/*
>>>    	 * FIXME:
>>>    	 * GEN8_SDEUNIT_CLOCK_GATE_DISABLE applies on A0 only.
>>> +	 * GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ applies on 3x6 GT SKUs only.

Shouldn't this WA therefore have a check for 3x6 around it?

>>>    	 */
>>>    	 /* WaDisableSDEUnitClockGating:bxt */
>>
>> I can't find where WaDisableSDEUnitClockGating is listed as required for
>> BXT?
>
> It's specified in BSpec GEN8_UCGCTL6 (0x9430) as required for BXT A0.
>
> --Imre
>