Em 18/06/2024 07:07, Dmitry Baryshkov escreveu:
On Tue, 18 Jun 2024 at 12:38, Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote:
On Tue, 18 Jun 2024, André Almeida <andrealmeid@xxxxxxxxxx> wrote:
Drivers have different capabilities on what plane types they can or
cannot perform async flips. Create a plane::async_flip field so each
driver can choose which planes they allow doing async flips.
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
include/drm/drm_plane.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index 9507542121fa..0bebc72af5c3 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -786,6 +786,11 @@ struct drm_plane {
* @kmsg_panic: Used to register a panic notifier for this plane
*/
struct kmsg_dumper kmsg_panic;
+
+ /**
+ * @async_flip: indicates if a plane can do async flips
+ */
When is it okay to set or change the value of this member?
If you don't document it, people will find creative uses for this.
Maybe it's better to have a callback instead of a static field? This
way it becomes clear that it's only relevant at the time of the
atomic_check().
So we would have something like bool (*async_flip) for struct
drm_plane_funcs I suppose. Then each driver will implement this function
and check on runtime if it should flip or not, right?
I agree that it makes more clear, but as far as I can see this is not
something that is subject to being changed at runtime at all, so it
seems a bit overkill to me to encapsulate a static information like
that. I prefer to improve the documentation on the struct member to see
if this solves the problem. What do you think of the following comment:
/**
* @async_flip: indicates if a plane can perform async flips. The
* driver should set this true only for planes that the hardware
* supports flipping asynchronously. It may not be changed during
* runtime. This field is checked inside drm_mode_atomic_ioctl() to
* allow only the correct planes to go with DRM_MODE_PAGE_FLIP_ASYNC.
*/
