[PATCH 2/2] drm/i915/lspcon: Separate lspcon probe and lspcon init

[Nautiyal, Ankit K]

On 3/25/2024 8:48 PM, Jani Nikula wrote:
> On Fri, 22 Mar 2024, Ankit Nautiyal <ankit.k.nautiyal at intel.com> wrote:
>> Currently we probe for lspcon, inside lspcon init. Which does 2 things:
>> probe the lspcon and set the expected LS/PCON mode.
>>
>> If there is no lspcon connected, the probe expectedly fails and
>> results in error message. This inturn gets propogated to
>> lspcon init and we get again error message for lspcon init
>> failure.
>>
>> Separate the probe function and avoid displaying error if probe fails.
>> If probe succeeds, only then start lspcon init and set the expected
>> LS/PCON mode as first step.
>>
>> While at it move the drm_err message in lspcon init, instead of the
>> caller.
>>
>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_dp.c     |  3 +++
>>   drivers/gpu/drm/i915/display/intel_lspcon.c | 27 +++++++++++----------
>>   drivers/gpu/drm/i915/display/intel_lspcon.h |  1 +
>>   3 files changed, 18 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 94fa34f77cf0..ea8d3e70127e 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -5882,6 +5882,9 @@ intel_dp_connector_register(struct drm_connector *connector)
>>   	 * ToDo: Clean this up to handle lspcon init and resume more
>>   	 * efficiently and streamlined.
>>   	 */
>> +	if (!lspcon_probe(lspcon))
>> +		return ret;
>> +
>>   	if (lspcon_init(dig_port)) {
>>   		lspcon_detect_hdr_capability(lspcon);
>>   		if (lspcon->hdr_supported)
>> diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.c b/drivers/gpu/drm/i915/display/intel_lspcon.c
>> index 62159d3ead56..570fde848d00 100644
>> --- a/drivers/gpu/drm/i915/display/intel_lspcon.c
>> +++ b/drivers/gpu/drm/i915/display/intel_lspcon.c
>> @@ -266,7 +266,7 @@ static bool lspcon_set_expected_mode(struct intel_lspcon *lspcon)
>>   	return true;
>>   }
>>   
>> -static bool lspcon_probe(struct intel_lspcon *lspcon)
>> +bool lspcon_probe(struct intel_lspcon *lspcon)
>>   {
>>   	int retry;
>>   	enum drm_dp_dual_mode_type adaptor_type;
>> @@ -676,30 +676,31 @@ bool lspcon_init(struct intel_digital_port *dig_port)
>>   	lspcon->active = false;
>>   	lspcon->mode = DRM_LSPCON_MODE_INVALID;
>>   
>> -	if (!lspcon_probe(lspcon)) {
>> -		drm_err(&i915->drm, "Failed to probe lspcon\n");
>> -		return false;
>> -	}
>> -
>>   	if (!lspcon_set_expected_mode(lspcon)) {
>>   		drm_err(&i915->drm, "LSPCON Set expected Mode failed\n");
>> -		return false;
>> +		goto lspcon_init_failed;
>>   	}
>>   
>>   	if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd) != 0) {
>>   		drm_err(&i915->drm, "LSPCON DPCD read failed\n");
>> -		return false;
>> +		goto lspcon_init_failed;
>>   	}
>>   
>>   	if (!lspcon_detect_vendor(lspcon)) {
>>   		drm_err(&i915->drm, "LSPCON vendor detection failed\n");
>> -		return false;
>> +		goto lspcon_init_failed;
>>   	}
>>   
>>   	connector->ycbcr_420_allowed = true;
>>   	lspcon->active = true;
>>   	drm_dbg_kms(&i915->drm, "Success: LSPCON init\n");
>>   	return true;
>> +
>> +lspcon_init_failed:
>> +	drm_err(&i915->drm, "LSPCON init failed on port %c\n",
>> +		port_name(dig_port->base.port));
> I guess the idea is to reduce dmesg errors, but in this function the
> error messages are multiplied.

Earlier we used to get the drm_error for init failure, even if the 
LSPCON was not detected, which is printed as a debug print.

Now we'll get the dmesg errors only if we detect lspcon and lspcon init 
indeed fails.

Regards,

Ankit


>
> BR,
> Jani.
>
>> +
>> +	return false;
>>   }
>>   
>>   u32 intel_lspcon_infoframes_enabled(struct intel_encoder *encoder,
>> @@ -721,11 +722,11 @@ void lspcon_resume(struct intel_digital_port *dig_port)
>>   		return;
>>   
>>   	if (!lspcon->active) {
>> -		if (!lspcon_init(dig_port)) {
>> -			drm_err(&i915->drm, "LSPCON init failed on port %c\n",
>> -				port_name(dig_port->base.port));
>> +		if (!lspcon_probe(lspcon))
>> +			return;
>> +
>> +		if (!lspcon_init(dig_port))
>>   			return;
>> -		}
>>   	}
>>   
>>   	if (lspcon_wake_native_aux_ch(lspcon)) {
>> diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.h b/drivers/gpu/drm/i915/display/intel_lspcon.h
>> index e19e10492b05..b156cc6b3a23 100644
>> --- a/drivers/gpu/drm/i915/display/intel_lspcon.h
>> +++ b/drivers/gpu/drm/i915/display/intel_lspcon.h
>> @@ -16,6 +16,7 @@ struct intel_encoder;
>>   struct intel_lspcon;
>>   
>>   bool lspcon_init(struct intel_digital_port *dig_port);
>> +bool lspcon_probe(struct intel_lspcon *lspcon);
>>   void lspcon_detect_hdr_capability(struct intel_lspcon *lspcon);
>>   void lspcon_resume(struct intel_digital_port *dig_port);
>>   void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon);