[PATCH v6 2/6] drm: introduce DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP

From: André Almeida
Date: Tue Aug 15 2023 - 14:59:04 EST


From: Simon Ser <contact@xxxxxxxxxxx>

This new kernel capability indicates whether async page-flips are
supported via the atomic uAPI. DRM clients can use it to check
for support before feeding DRM_MODE_PAGE_FLIP_ASYNC to the kernel.

Make it clear that DRM_CAP_ASYNC_PAGE_FLIP is for legacy uAPI only.

Signed-off-by: Simon Ser <contact@xxxxxxxxxxx>
Reviewed-by: André Almeida <andrealmeid@xxxxxxxxxx>
Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
v5: no changes
v4: no changes
---
drivers/gpu/drm/drm_ioctl.c | 5 +++++
include/uapi/drm/drm.h | 10 +++++++++-
2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index f03ffbacfe9b..3562b717b74f 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -301,6 +301,11 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_
case DRM_CAP_CRTC_IN_VBLANK_EVENT:
req->value = 1;
break;
+ case DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP:
+ req->value = drm_core_check_feature(dev, DRIVER_ATOMIC) &&
+ dev->mode_config.async_page_flip &&
+ !dev->mode_config.atomic_async_page_flip_not_supported;
+ break;
default:
return -EINVAL;
}
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index 794c1d857677..58baefe32c23 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -713,7 +713,8 @@ struct drm_gem_open {
/**
* DRM_CAP_ASYNC_PAGE_FLIP
*
- * If set to 1, the driver supports &DRM_MODE_PAGE_FLIP_ASYNC.
+ * If set to 1, the driver supports &DRM_MODE_PAGE_FLIP_ASYNC for legacy
+ * page-flips.
*/
#define DRM_CAP_ASYNC_PAGE_FLIP 0x7
/**
@@ -773,6 +774,13 @@ struct drm_gem_open {
* :ref:`drm_sync_objects`.
*/
#define DRM_CAP_SYNCOBJ_TIMELINE 0x14
+/**
+ * DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP
+ *
+ * If set to 1, the driver supports &DRM_MODE_PAGE_FLIP_ASYNC for atomic
+ * commits.
+ */
+#define DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP 0x15

/* DRM_IOCTL_GET_CAP ioctl argument type */
struct drm_get_cap {
--
2.41.0