[PATCH 1/3] drm/debug: Expose connector's max supported bpc via debugfs

[Modem, Bhanuprakash]

On Fri-08-04-2022 08:32 pm, Harry Wentland wrote:
> 
> 
> On 2022-04-08 02:53, Bhanuprakash Modem wrote:
>> It's useful to know the connector's max supported bpc for IGT
>> testing. Expose it via a debugfs file on the connector "output_bpc".
>>
>> Example: cat /sys/kernel/debug/dri/0/DP-1/output_bpc
>>
>> Cc: Jani Nikula <jani.nikula at linux.intel.com>
>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> Cc: Harry Wentland <harry.wentland at amd.com>
>> Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
>> ---
>>   drivers/gpu/drm/drm_debugfs.c | 21 +++++++++++++++++++++
>>   1 file changed, 21 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
>> index 7f1b82dbaebb..33e5345c6f3e 100644
>> --- a/drivers/gpu/drm/drm_debugfs.c
>> +++ b/drivers/gpu/drm/drm_debugfs.c
>> @@ -395,6 +395,23 @@ static int vrr_range_show(struct seq_file *m, void *data)
>>   }
>>   DEFINE_SHOW_ATTRIBUTE(vrr_range);
>>   
>> +/*
>> + * Returns Connector's max supported bpc through debugfs file.
>> + * Example usage: cat /sys/kernel/debug/dri/0/DP-1/max_bpc
> 
> /s/max_bpc/output_bpc
> 
> Btw, in amdgpu we have both max_bpc and output_bpc.

I'll float a new rev, Thanks.

- Bhanu

> 
> Harry
> 
>> + */
>> +static int output_bpc_show(struct seq_file *m, void *data)
>> +{
>> +	struct drm_connector *connector = m->private;
>> +
>> +	if (connector->status != connector_status_connected)
>> +		return -ENODEV;
>> +
>> +	seq_printf(m, "Maximum: %u\n", connector->display_info.bpc);
>> +
>> +	return 0;
>> +}
>> +DEFINE_SHOW_ATTRIBUTE(output_bpc);
>> +
>>   static const struct file_operations drm_edid_fops = {
>>   	.owner = THIS_MODULE,
>>   	.open = edid_open,
>> @@ -437,6 +454,10 @@ void drm_debugfs_connector_add(struct drm_connector *connector)
>>   	debugfs_create_file("vrr_range", S_IRUGO, root, connector,
>>   			    &vrr_range_fops);
>>   
>> +	/* max bpc */
>> +	debugfs_create_file("output_bpc", 0444, root, connector,
>> +			    &output_bpc_fops);
>> +
>>   	if (connector->funcs->debugfs_init)
>>   		connector->funcs->debugfs_init(connector, root);
>>   }
>