Re: [PATCH v4 04/13] drm/i915/display: Add DC3CO DC_STATE enable/disable support

[Dibin Moolakadan Subrahmanian <dibin.moolakadan.subrahmanian@intel.com>]

On 01-06-2026 11:12, Manna, Animesh wrote:
>
>> -----Original Message-----
>> From: Dibin Moolakadan Subrahmanian
>> <dibin.moolakadan.subrahmanian@intel.com>
>> Sent: Wednesday, May 27, 2026 12:48 AM
>> To: intel-gfx@lists.freedesktop.org; intel-xe@lists.freedesktop.org
>> Cc: Manna, Animesh <animesh.manna@intel.com>; Shankar, Uma
>> <uma.shankar@intel.com>
>> Subject: [PATCH v4 04/13] drm/i915/display: Add DC3CO DC_STATE
>> enable/disable support
>>
>> Add DC3CO handling to the dc_off power well sequencing and disable the
>> DMC wakelock when exiting DC3CO.
>>
>> BSpec: 75253
>> Signed-off-by: Dibin Moolakadan Subrahmanian
>> <dibin.moolakadan.subrahmanian@intel.com>
>> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
>> ---
>>   .../drm/i915/display/intel_display_power_well.c  | 16 +++++++++++++++-
>>   1 file changed, 15 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_display_power_well.c
>> b/drivers/gpu/drm/i915/display/intel_display_power_well.c
>> index 611f784d8a7a..3ea080d0e21e 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display_power_well.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c
>> @@ -866,6 +866,13 @@ void gen9_set_dc_state(struct intel_display *display,
>> u32 state)
>>   	power_domains->dc_state = val & mask;
>>   }
>>
>> +static void xe3lpd_enable_dc3co(struct intel_display *display) {
> Better to add a assert_can_enable_dc3co() which is followed for other dc-state programming.
Thanks, I'll  add this check in the next revision.
>
> Regards,
> Animesh
>
>> +	drm_dbg_kms(display->drm, "Enabling DC3CO\n");
>> +	intel_dmc_wl_enable(display, DC_STATE_EN_UPTO_DC3CO);
>> +	gen9_set_dc_state(display, DC_STATE_EN_UPTO_DC3CO); }
>> +
>>   static void assert_can_enable_dc5(struct intel_display *display)  {
>>   	enum i915_power_well_id high_pg;
>> @@ -1054,9 +1061,13 @@ void gen9_disable_dc_states(struct intel_display
>> *display)
>>   	}
>>
>>   	if (old_state == DC_STATE_EN_UPTO_DC5 ||
>> -	    old_state == DC_STATE_EN_UPTO_DC6)
>> +	    old_state == DC_STATE_EN_UPTO_DC6 ||
>> +	    old_state == DC_STATE_EN_UPTO_DC3CO)
>>   		intel_dmc_wl_disable(display);
>>
>> +	if (old_state == DC_STATE_EN_UPTO_DC3CO)
>> +		return;
>> +
>>   	intel_cdclk_get_cdclk(display, &cdclk_config);
>>   	/* Can't read out voltage_level so can't use intel_cdclk_changed() */
>>   	drm_WARN_ON(display->drm,
>> @@ -1092,6 +1103,9 @@ static void gen9_dc_off_power_well_disable(struct
>> intel_display *display,
>>   		return;
>>
>>   	switch (power_domains->target_dc_state) {
>> +	case DC_STATE_EN_UPTO_DC3CO:
>> +		xe3lpd_enable_dc3co(display);
>> +		break;
>>   	case DC_STATE_EN_UPTO_DC6:
>>   		skl_enable_dc6(display);
>>   		break;
>> --
>> 2.43.0