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

[Christian König]

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>

> ---
>   .../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)