[PATCH 1/3] drm/amd/display: Add module parameter for freesync video mode

[Kazlauskas, Nicholas]

On 2020-12-09 9:45 p.m., Aurabindo Pillai wrote:
> [Why&How]
> Adds a module parameter to enable experimental freesync video mode modeset
> optimization. Enabling this mode allows the driver to skip a full modeset when
> freesync compatible modes are requested by the userspace. This paramters also
> adds some standard modes based on the connected monitor's VRR range.
> 
> Signed-off-by: Aurabindo Pillai <aurabindo.pillai at amd.com>

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h     |  1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 12 ++++++++++++
>   2 files changed, 13 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 83ac06a3ec05..efbfee93c359 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -177,6 +177,7 @@ extern int amdgpu_gpu_recovery;
>   extern int amdgpu_emu_mode;
>   extern uint amdgpu_smu_memory_pool_size;
>   extern uint amdgpu_dc_feature_mask;
> +extern uint amdgpu_exp_freesync_vid_mode;
>   extern uint amdgpu_dc_debug_mask;
>   extern uint amdgpu_dm_abm_level;
>   extern struct amdgpu_mgpu_info mgpu_info;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index b2a1dd7581bf..ece51ecd53d1 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -158,6 +158,7 @@ int amdgpu_mes;
>   int amdgpu_noretry = -1;
>   int amdgpu_force_asic_type = -1;
>   int amdgpu_tmz;
> +uint amdgpu_exp_freesync_vid_mode;
>   int amdgpu_reset_method = -1; /* auto */
>   int amdgpu_num_kcq = -1;
>   
> @@ -786,6 +787,17 @@ module_param_named(abmlevel, amdgpu_dm_abm_level, uint, 0444);
>   MODULE_PARM_DESC(tmz, "Enable TMZ feature (-1 = auto, 0 = off (default), 1 = on)");
>   module_param_named(tmz, amdgpu_tmz, int, 0444);
>   
> +/**
> + * DOC: experimental_freesync_video (uint)
> + * Enabled the optimization to adjust front porch timing to achieve seamless mode change experience
> + * when setting a freesync supported mode for which full modeset is not needed.
> + * The default value: 0 (off).
> + */
> +MODULE_PARM_DESC(
> +	experimental_freesync_video,
> +	"Enable freesync modesetting optimization feature (0 = off (default), 1 = on)");
> +module_param_named(experimental_freesync_video, amdgpu_exp_freesync_vid_mode, uint, 0444);
> +
>   /**
>    * DOC: reset_method (int)
>    * GPU reset method (-1 = auto (default), 0 = legacy, 1 = mode0, 2 = mode1, 3 = mode2, 4 = baco)
>