Re: [PATCH] drm/i915/chv: Use timeout mode for RC6 on chv

[Deepak S <deepak.s@linux.intel.com>]

On Monday 21 July 2014 10:42 PM, Ben Widawsky wrote:
> On Tue, Jul 22, 2014 at 01:50:20PM +0530, Deepak S wrote:
>> On Thursday 17 July 2014 09:16 AM, deepak.s@linux.intel.com wrote:
>>> From: Deepak S <deepak.s@linux.intel.com>
>>>
>>> Higher RC6 residency is observed using timeout mode
>>> instead of EI mode. It's Recommended to use TO Method for RC6.
>>>
>>> Signed-off-by: Deepak S <deepak.s@linux.intel.com>
>>> ---
>>>   drivers/gpu/drm/i915/intel_pm.c | 4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>>> index 19c5c26..88bad36 100644
>>> --- a/drivers/gpu/drm/i915/intel_pm.c
>>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>>> @@ -4037,7 +4037,7 @@ static void cherryview_enable_rps(struct drm_device *dev)
>>>   		I915_WRITE(RING_MAX_IDLE(ring->mmio_base), 10);
>>>   	I915_WRITE(GEN6_RC_SLEEP, 0);
>>> -	I915_WRITE(GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
>>> +	I915_WRITE(GEN6_RC6_THRESHOLD, 0x557);
>>>   	/* allows RC6 residency counter to work */
>>>   	I915_WRITE(VLV_COUNTER_CONTROL,
>>> @@ -4053,7 +4053,7 @@ static void cherryview_enable_rps(struct drm_device *dev)
>>>   	/* 3: Enable RC6 */
>>>   	if ((intel_enable_rc6(dev) & INTEL_RC6_ENABLE) &&
>>>   						(pcbr >> VLV_PCBR_ADDR_SHIFT))
>>> -		rc6_mode = GEN6_RC_CTL_EI_MODE(1);
>>> +		rc6_mode = GEN7_RC_CTL_TO_MODE;
>>>   	I915_WRITE(GEN6_RC_CONTROL, rc6_mode);
>> Hi Ben,
>>
>> Please review the patch
> Why me? I don't know anything about Cherryview. I only put the r-b on
> the BDW version because of the public QA data which showed it was a win
> for power without hurting performance.
>
> I'd suggest you get Tom O'Rourke to review this.

Thanks Ben, I will check with Tom.

>> Thanks
>> Deepak
>>