Re: [PATCH] drm/i915/dp: ALPM init to be done after DPCD init

["Murthy, Arun R" <arun.r.murthy@intel.com>]

On 02-03-2026 12:14, Hogander, Jouni wrote:
> On Mon, 2026-03-02 at 09:06 +0530, Arun R Murthy wrote:
>> In ALPM init, the DPCD register ALPM_CAPABILITIES are to be read.
>> This
>> read has to happen after the DPCD init.
>>
>> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>> b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 613559d11133..e60802b0b8c9 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -6948,8 +6948,6 @@ static bool intel_edp_init_connector(struct
>> intel_dp *intel_dp,
>>   	 */
>>   	intel_hpd_enable_detection(encoder);
>>   
>> -	intel_alpm_init(intel_dp);
>> -
>>   	/* Cache DPCD and EDID for edp. */
>>   	has_dpcd = intel_edp_init_dpcd(intel_dp, connector);
>>   
>> @@ -6961,6 +6959,8 @@ static bool intel_edp_init_connector(struct
>> intel_dp *intel_dp,
>>   		goto out_vdd_off;
>>   	}
>>   
>> +	intel_alpm_init(intel_dp);
> This will cause problems to PSR/Panel Replay. intel_psr_init_dpcd is
> relying on ALPM dpcd init is done first.
>
> BR,
> Jouni Högander

I think this will also have to be moved down.

For eDP intel_psr_init_dpcd() is called in intel_edp_init_dpcd. So can 
we move intel_alpm_init inside intel_edp_init_dpcd() ? Just before 
calling intel_psr_init_dpcd !
Also rename intel_alpm_init() to intel_alpm_init_dpcd() ?

Thanks and Regards,
Arun R Murthy
--------------------

>> +
>>   	/*
>>   	 * VBT and straps are liars. Also check HPD as that seems
>>   	 * to be the most reliable piece of information available.