[Intel-gfx] [PATCH v9 8/8] drm/i915: Enable async flips in i915

[Karthik B S]

On 9/18/2020 5:33 PM, Ville Syrjälä wrote:
> On Wed, Sep 16, 2020 at 08:38:24PM +0530, Karthik B S wrote:
>> Enable asynchronous flips in i915 for gen9+ platforms.
>>
>> v2: -Async flip enablement should be a stand alone patch (Paulo)
>>
>> v3: -Move the patch to the end of the series (Paulo)
>>
>> v4: -Rebased.
>>
>> v5: -Rebased.
>>
>> v6: -Rebased.
>>
>> v7: -Rebased.
>>
>> v8: -Rebased.
>>
>> v9: -Rebased.
>>
>> Signed-off-by: Karthik B S <karthik.b.s at intel.com>
>> Signed-off-by: Vandita Kulkarni <vandita.kulkarni at intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_display.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
>> index 6f6edc581e14..e31abf5f1a9d 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>> @@ -18021,6 +18021,9 @@ static void intel_mode_config_init(struct drm_i915_private *i915)
>>   
>>   	mode_config->funcs = &intel_mode_funcs;
>>   
>> +	if (INTEL_GEN(i915) >= 9)
>> +		mode_config->async_page_flip = true;
>> +
> 
> Should have all we need for those platforms I think.
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 

Thanks for the RB.

> The followup to enable it for ilk+ would require a slight change to
> bump X-tiled surface alignment to 256KiB. Apart from the actual regiser
> smashing part that should be all we need really.
> 
> Oh, and the double buffer bit w/a will also be needed on bdw.
> I've now tested snb/ivb/hsw/bdw and only bdw needs it. I guess
> that's not entirely unsurpising since bdw did introduce one other
> fail for the flip done interrupt (the interupt fires immediately
> when the plane was disabled, so can't use flip done to determine
> when the plane has actually become visible). Fortunately that
> other fail should have no impact on using it for async flip
> completion.
> 

Sure I'll make the mentioned changes in the followup patches to enable 
async flip for ilk+ platforms.

Thanks,
Karthik.B.S
>>   	/*
>>   	 * Maximum framebuffer dimensions, chosen to match
>>   	 * the maximum render engine surface size on gen4+.
>> -- 
>> 2.22.0
>