Re: [PATCH v2 2/2] drm/amdgpu: Implement check_async_props for planes

Harry Wentland
2024-01-22T15:50:55Z

On 2024-01-19 13:25, Ville Syrjälä wrote:
> On Fri, Jan 19, 2024 at 03:12:35PM -0300, André Almeida wrote:
>> AMD GPUs can do async flips with changes on more properties than just
>> the FB ID, so implement a custom check_async_props for AMD planes.
>>
>> Allow amdgpu to do async flips with IN_FENCE_ID and FB_DAMAGE_CLIPS
>> properties. For userspace to check if a driver support this two
>> properties, the strategy for now is to use TEST_ONLY commits.
>>
>> Signed-off-by: André Almeida <andrealmeid@igalia.com>
>> ---
>> v2: Drop overlay plane option for now
>>
>> .../amd/display/amdgpu_dm/amdgpu_dm_plane.c | 29 +++++++++++++++++++
>> 1 file changed, 29 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
>> index 116121e647ca..7afe8c1b62d4 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
>> @@ -25,6 +25,7 @@
>> */
>>
>> #include <drm/drm_atomic_helper.h>
>> +#include <drm/drm_atomic_uapi.h>
>> #include <drm/drm_blend.h>
>> #include <drm/drm_gem_atomic_helper.h>
>> #include <drm/drm_plane_helper.h>
>> @@ -1430,6 +1431,33 @@ static void amdgpu_dm_plane_drm_plane_destroy_state(struct drm_plane *plane,
>> drm_atomic_helper_plane_destroy_state(plane, state);
>> }
>>
>> +static int amdgpu_dm_plane_check_async_props(struct drm_property *prop,
>> + struct drm_plane *plane,
>> + struct drm_plane_state *plane_state,
>> + struct drm_mode_object *obj,
>> + u64 prop_value, u64 old_val)
>> +{
>> + struct drm_mode_config *config = &plane->dev->mode_config;
>> + int ret;
>> +
>> + if (prop != config->prop_fb_id &&
>> + prop != config->prop_in_fence_fd &&
>
> IN_FENCE should just be allowed always.
>
>> + prop != config->prop_fb_damage_clips) {
>
> This seems a bit dubious to me. How is amdgpu using the damage
> information during async flips?

Yeah, I'm also not sure this is right. Has anyone tested this
with a PSR SU panel?

Harry

>
>> + ret = drm_atomic_plane_get_property(plane, plane_state,
>> + prop, &old_val);
>> + return drm_atomic_check_prop_changes(ret, old_val, prop_value, prop);
>> + }
>> +
>> + if (plane_state->plane->type != DRM_PLANE_TYPE_PRIMARY) {
>> + drm_dbg_atomic(prop->dev,
>> + "[OBJECT:%d] Only primary planes can be changed during async flip\n",
>> + obj->id);
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> static const struct drm_plane_funcs dm_plane_funcs = {
>> .update_plane = drm_atomic_helper_update_plane,
>> .disable_plane = drm_atomic_helper_disable_plane,
>> @@ -1438,6 +1466,7 @@ static const struct drm_plane_funcs dm_plane_funcs = {
>> .atomic_duplicate_state = amdgpu_dm_plane_drm_plane_duplicate_state,
>> .atomic_destroy_state = amdgpu_dm_plane_drm_plane_destroy_state,
>> .format_mod_supported = amdgpu_dm_plane_format_mod_supported,
>> + .check_async_props = amdgpu_dm_plane_check_async_props,
>> };
>>
>> int amdgpu_dm_plane_init(struct amdgpu_display_manager *dm,
>> --
>> 2.43.0
>