Re: [Intel-gfx] [PATCH 4/7] drm/i915/bios: use alternate aux channel directly from child data

[Jani Nikula <jani.nikula@intel.com>]

On Thu, 26 Aug 2021, "Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com> wrote:
> On 8/24/2021 7:04 PM, Jani Nikula wrote:
>> Avoid extra caching of the data.
>>
>> Cc: José Roberto de Souza <jose.souza@intel.com>
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_bios.c | 26 +++++++++++------------
>>   drivers/gpu/drm/i915/i915_drv.h           |  1 -
>>   2 files changed, 12 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
>> index 10b2beddc121..674f1424fcc2 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
>> @@ -1565,28 +1565,29 @@ static enum port get_port_by_aux_ch(struct drm_i915_private *i915, u8 aux_ch)
>>   	for_each_port(port) {
>>   		info = &i915->vbt.ddi_port_info[port];
>>   
>> -		if (info->devdata && aux_ch == info->alternate_aux_channel)
>> +		if (info->devdata && aux_ch == info->devdata->child.aux_channel)
>>   			return port;
>>   	}
>>   
>>   	return PORT_NONE;
>>   }
>>   
>> -static void sanitize_aux_ch(struct drm_i915_private *i915,
>> +static void sanitize_aux_ch(struct intel_bios_encoder_data *devdata,
>>   			    enum port port)
>>   {
>> -	struct ddi_vbt_port_info *info = &i915->vbt.ddi_port_info[port];
>> +	struct drm_i915_private *i915 = devdata->i915;
>> +	struct ddi_vbt_port_info *info;
>>   	struct child_device_config *child;
>>   	enum port p;
>>   
>> -	p = get_port_by_aux_ch(i915, info->alternate_aux_channel);
>> +	p = get_port_by_aux_ch(i915, devdata->child.aux_channel);
>>   	if (p == PORT_NONE)
>>   		return;
>>   
>>   	drm_dbg_kms(&i915->drm,
>>   		    "port %c trying to use the same AUX CH (0x%x) as port %c, "
>>   		    "disabling port %c DP support\n",
>> -		    port_name(port), info->alternate_aux_channel,
>> +		    port_name(port), devdata->child.aux_channel,
>>   		    port_name(p), port_name(p));
>>   
>>   	/*
>> @@ -1602,7 +1603,7 @@ static void sanitize_aux_ch(struct drm_i915_private *i915,
>>   	child = &info->devdata->child;
>>   
>>   	child->device_type &= ~DEVICE_TYPE_DISPLAYPORT_OUTPUT;
>> -	info->alternate_aux_channel = 0;
>> +	child->aux_channel = 0;
>>   }
>>   
>>   static const u8 cnp_ddc_pin_map[] = {
>> @@ -1980,11 +1981,8 @@ static void parse_ddi_port(struct drm_i915_private *i915,
>>   		}
>>   	}
>>   
>> -	if (is_dp) {
>> -		info->alternate_aux_channel = child->aux_channel;
>> -
>> -		sanitize_aux_ch(i915, port);
>> -	}
>> +	if (is_dp)
>> +		sanitize_aux_ch(devdata, port);
>>   
>>   	hdmi_level_shift = _intel_bios_hdmi_level_shift(devdata);
>>   	if (hdmi_level_shift >= 0) {
>> @@ -2863,7 +2861,7 @@ enum aux_ch intel_bios_port_aux_ch(struct drm_i915_private *i915,
>>   		&i915->vbt.ddi_port_info[port];
>>   	enum aux_ch aux_ch;
>>   
>> -	if (!info->alternate_aux_channel) {
>> +	if (!info->devdata->child.aux_channel) {
>
> Hi Jani,
>
> The series and the change make sense to me.
>
>  From the CI results it seems that cases with LVDS panel connected are 
> getting issues here.
>
> Apparently info->devdata is not set in this case. I guess that, 
> parse_ddi_port() returns early before info->devdata gets set.
>
> I think without the patch, this situation is not encountered due to the 
> fact that 'info->alternate_aux_channel, is initialized to 0.
>
> With this change, perhaps we should check for 'info->devdata' before 
> checking for info->devdata->child.aux_channel.
>
> (This will translate to checking for 'devdata' in the final patch as it 
> removes ddi_port_info).
>
> Hope it helps.

Yes, indeed, thanks for figuring this out!

And thanks for the reviews.

BR,
Jani.


>
> Regards,
>
> Ankit
>
>
>>   		aux_ch = (enum aux_ch)port;
>>   
>>   		drm_dbg_kms(&i915->drm,
>> @@ -2879,7 +2877,7 @@ enum aux_ch intel_bios_port_aux_ch(struct drm_i915_private *i915,
>>   	 * ADL-S VBT uses PHY based mapping. Combo PHYs A,B,C,D,E
>>   	 * map to DDI A,TC1,TC2,TC3,TC4 respectively.
>>   	 */
>> -	switch (info->alternate_aux_channel) {
>> +	switch (info->devdata->child.aux_channel) {
>>   	case DP_AUX_A:
>>   		aux_ch = AUX_CH_A;
>>   		break;
>> @@ -2940,7 +2938,7 @@ enum aux_ch intel_bios_port_aux_ch(struct drm_i915_private *i915,
>>   			aux_ch = AUX_CH_I;
>>   		break;
>>   	default:
>> -		MISSING_CASE(info->alternate_aux_channel);
>> +		MISSING_CASE(info->devdata->child.aux_channel);
>>   		aux_ch = AUX_CH_A;
>>   		break;
>>   	}
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index a0dead9f9222..91097526cd96 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -640,7 +640,6 @@ struct ddi_vbt_port_info {
>>   	/* Non-NULL if port present. */
>>   	struct intel_bios_encoder_data *devdata;
>>   
>> -	u8 alternate_aux_channel;
>>   	u8 alternate_ddc_pin;
>>   };
>>   

-- 
Jani Nikula, Intel Open Source Graphics Center