[PATCH 16/19] drm/i915/display: Use fixed_rr timings in modeset sequence

Nautiyal, Ankit K ankit.k.nautiyal at intel.com
Wed Feb 19 13:17:20 UTC 2025


On 2/18/2025 12:04 AM, Ville Syrjälä wrote:
> On Fri, Feb 14, 2025 at 05:41:26PM +0530, Ankit Nautiyal wrote:
>> During modeset enable sequence, program the fixed timings,
>> and turn on the VRR Timing Generator (VRR TG) for platforms
>> that always use VRR TG.
>>
>> Later if vrr timings are required, vrr_enable() will switch
>> to the real VRR timings.
>>
>> With this we dont want to reset TRANS_CTL_VRR Enable bit while updating
>> the vrr transcoder timings.
>>
>> v2: Update intel_vrr_set_transcoder_timings for fixed_rr.
>> v3: Update intel_set_transcoder_timings_lrr for fixed_rr. (Ville)
>>      Add TRANS_PUSH while enabling VRR for fixed_rr.
>>
>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_display.c | 10 +++++--
>>   drivers/gpu/drm/i915/display/intel_vrr.c     | 29 ++++++++++++++++++--
>>   drivers/gpu/drm/i915/display/intel_vrr.h     |  3 ++
>>   3 files changed, 36 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
>> index 66c5ad46bfea..c9d1c091b109 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>> @@ -1755,6 +1755,7 @@ static void hsw_set_frame_start_delay(const struct intel_crtc_state *crtc_state)
>>   
>>   static void hsw_configure_cpu_transcoder(const struct intel_crtc_state *crtc_state)
>>   {
>> +	struct intel_display *display = to_intel_display(crtc_state);
>>   	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>>   	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>>   	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
>> @@ -1770,9 +1771,12 @@ static void hsw_configure_cpu_transcoder(const struct intel_crtc_state *crtc_sta
>>   	}
>>   
>>   	intel_set_transcoder_timings(crtc_state);
>> -	if (HAS_VRR(dev_priv))
>> -		intel_vrr_set_transcoder_timings(crtc_state);
>> -
>> +	if (HAS_VRR(dev_priv)) {
>> +		if (intel_vrr_always_use_vrr_tg(display))
>> +			intel_vrr_enable_fixed_rr_timings(crtc_state);
>> +		else
>> +			intel_vrr_set_transcoder_timings(crtc_state);
> I think intel_vrr_set_transcoder_timings() should just program the
> fixed timings always. And we shouldn't do anything else here.
>
> And I think the VRR_CTL enable/disable for the always_use_vrr_tg==true
> case should be done at some more appropriate spot in the modeset
> sequence. We can add eg. intel_vrr_trancoder_{enable,disable}() for
> that part.

Alright. So will do the following changes:
In intel_vrr_set_transcoder:
-Avoid modifying VRR_CTL, currently, it disables VRR_VTL if flipline is 
not set, and also writes guardband and other settings in VRR_CTL.

-Instead of setting variable timings, just set the fixed timings always.

Use separate functions for enabling/disabling VRR CTL:
-As suggested will create intel_vrr_transcoder_enable and 
intel_vrr_transcoder_disable functions.
-These functions should handle VRR_CTL settings for platforms where TG 
is not always used.
-I am thinking to call these functions based on vrr.flipline:

if (is_enabling(vrr.flipline, old_crtc_state, new_crtc_state))
     intel_vrr_transcoder_enable(new_crtc_state)

Thinking to add this in commit_pipe_post_planes() just before 
intel_vrr_enable().

if (is_disabling(vrr.flipline, old_crtc_state, new_crtc_state))
     intel_vrr_transcoder_disable(new_crtc_state)

Will try adding this in intel_pre_plane_update() after intel_vrr_disable().

Please correct me if I have missed something or got something wrong.

Regards,

Ankit

>> +	}
>>   	if (cpu_transcoder != TRANSCODER_EDP)
>>   		intel_de_write(dev_priv, TRANS_MULT(dev_priv, cpu_transcoder),
>>   			       crtc_state->pixel_multiplier - 1);
>> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
>> index e247055bc486..4151fcd0f978 100644
>> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
>> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
>> @@ -456,8 +456,12 @@ void intel_vrr_set_transcoder_timings(const struct intel_crtc_state *crtc_state)
>>   		       crtc_state->vrr.vmin - 1);
>>   	intel_de_write(display, TRANS_VRR_VMAX(display, cpu_transcoder),
>>   		       crtc_state->vrr.vmax - 1);
>> -	intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder),
>> -		       trans_vrr_ctl(crtc_state));
>> +	if (intel_vrr_always_use_vrr_tg(display))
>> +		intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder),
>> +			       VRR_CTL_VRR_ENABLE | trans_vrr_ctl(crtc_state));
>> +	else
>> +		intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder),
>> +			       trans_vrr_ctl(crtc_state));
> We should probably remove this VRR_CTL frobbing from here entirely,
> and just always do it from the intel_vrr_trancoder_{enable,disable}().
> And obviously for the !always_use_vrr_tg case we just skip setting
> the enable bit there.
>
>>   	intel_de_write(display, TRANS_VRR_FLIPLINE(display, cpu_transcoder),
>>   		       crtc_state->vrr.flipline - 1);
>>   
>> @@ -536,7 +540,6 @@ bool intel_vrr_is_push_sent(const struct intel_crtc_state *crtc_state)
>>   	return intel_de_read(display, TRANS_PUSH(display, cpu_transcoder)) & TRANS_PUSH_SEND;
>>   }
>>   
>> -static
>>   bool intel_vrr_always_use_vrr_tg(struct intel_display *display)
>>   {
>>   	if (!HAS_VRR(display))
>> @@ -616,6 +619,26 @@ void intel_vrr_disable(const struct intel_crtc_state *old_crtc_state)
>>   	intel_vrr_set_fixed_rr_timings(old_crtc_state);
>>   }
>>   
>> +void intel_vrr_enable_fixed_rr_timings(const struct intel_crtc_state *crtc_state)
>> +{
>> +	struct intel_display *display = to_intel_display(crtc_state);
>> +	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
>> +
>> +	intel_vrr_set_fixed_rr_timings(crtc_state);
>> +
>> +	if (HAS_AS_SDP(display))
>> +		intel_de_write(display,
>> +			       TRANS_VRR_VSYNC(display, cpu_transcoder),
>> +			       VRR_VSYNC_END(crtc_state->vrr.vsync_end) |
>> +			       VRR_VSYNC_START(crtc_state->vrr.vsync_start));
>> +
>> +	intel_de_write(display, TRANS_PUSH(display, cpu_transcoder),
>> +		       TRANS_PUSH_EN);
>> +
>> +	intel_de_write(display, TRANS_VRR_CTL(display, cpu_transcoder),
>> +		       VRR_CTL_VRR_ENABLE | trans_vrr_ctl(crtc_state));
>> +}
>> +
>>   static
>>   bool intel_vrr_is_fixed_rr(const struct intel_crtc_state *crtc_state)
>>   {
>> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.h b/drivers/gpu/drm/i915/display/intel_vrr.h
>> index 514822577e8a..9259964978b1 100644
>> --- a/drivers/gpu/drm/i915/display/intel_vrr.h
>> +++ b/drivers/gpu/drm/i915/display/intel_vrr.h
>> @@ -12,6 +12,7 @@ struct drm_connector_state;
>>   struct intel_atomic_state;
>>   struct intel_connector;
>>   struct intel_crtc_state;
>> +struct intel_display;
>>   struct intel_dsb;
>>   
>>   bool intel_vrr_is_capable(struct intel_connector *connector);
>> @@ -35,5 +36,7 @@ int intel_vrr_vmin_vtotal(const struct intel_crtc_state *crtc_state);
>>   int intel_vrr_vmax_vblank_start(const struct intel_crtc_state *crtc_state);
>>   int intel_vrr_vmin_vblank_start(const struct intel_crtc_state *crtc_state);
>>   int intel_vrr_vblank_delay(const struct intel_crtc_state *crtc_state);
>> +bool intel_vrr_always_use_vrr_tg(struct intel_display *display);
>> +void intel_vrr_enable_fixed_rr_timings(const struct intel_crtc_state *crtc_state);
>>   
>>   #endif /* __INTEL_VRR_H__ */
>> -- 
>> 2.45.2


More information about the Intel-xe mailing list