[PATCH] drm/amd/display: Expose connector VRR range via debugfs

[Wentland, Harry]

On 2019-01-24 12:41 p.m., Christian König wrote:
> Am 24.01.19 um 18:06 schrieb Nicholas Kazlauskas:
>> [Why]
>> It's useful to know the min and max vrr range for IGT testing.
>>
>> [How]
>> Expose the min and max vfreq for the connector via a debugfs file
>> on the connector, "vrr_range".
>>
>> Example usage: cat /sys/kernel/debug/dri/0/DP-1/vrr_range
>>
>> Cc: Harry Wentland <harry.wentland at amd.com>
>> Cc: Leo Li <sunpeng.li at amd.com>
>> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
> 
> Oh, nice that is indeed useful. Acked-by: Christian König <christian.koenig at amd.com>
> 

FYI, IGT test case making use of this: https://patchwork.freedesktop.org/patch/275982/

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry

>> ---
>>   .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 22 ++++++++++++++++++-
>>   1 file changed, 21 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>> index cca3e16cda4f..4a55cde027cf 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>> @@ -671,6 +671,25 @@ static ssize_t dp_phy_test_pattern_debugfs_write(struct file *f, const char __us
>>       return bytes_from_user;
>>   }
>>   +/*
>> + * Returns the min and max vrr vfreq through the connector's debugfs file.
>> + * Example usage: cat /sys/kernel/debug/dri/0/DP-1/vrr_range
>> + */
>> +static int vrr_range_show(struct seq_file *m, void *data)
>> +{
>> +    struct drm_connector *connector = m->private;
>> +    struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
>> +
>> +    if (connector->status != connector_status_connected)
>> +        return -ENODEV;
>> +
>> +    seq_printf(m, "Min: %u\n", (unsigned int)aconnector->min_vfreq);
>> +    seq_printf(m, "Max: %u\n", (unsigned int)aconnector->max_vfreq);
>> +
>> +    return 0;
>> +}
>> +DEFINE_SHOW_ATTRIBUTE(vrr_range);
>> +
>>   static const struct file_operations dp_link_settings_debugfs_fops = {
>>       .owner = THIS_MODULE,
>>       .read = dp_link_settings_read,
>> @@ -697,7 +716,8 @@ static const struct {
>>   } dp_debugfs_entries[] = {
>>           {"link_settings", &dp_link_settings_debugfs_fops},
>>           {"phy_settings", &dp_phy_settings_debugfs_fop},
>> -        {"test_pattern", &dp_phy_test_pattern_fops}
>> +        {"test_pattern", &dp_phy_test_pattern_fops},
>> +        {"vrr_range", &vrr_range_fops}
>>   };
>>     int connector_debugfs_init(struct amdgpu_dm_connector *connector)
>