Although the current DRM_IOCTL_MODE_CREATE_DUMB interface design only suits linear buffers, some KMS drivers abuse it for AFBC framebuffers.
Mention it in the interface document, and clarifying that it's not recommended. Signed-off-by: Icenowy Zheng <[email protected]> --- include/uapi/drm/drm_mode.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index cbbbfc1dfe2b8..02b6fa7ade355 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -1256,6 +1256,10 @@ struct drm_mode_crtc_page_flip_target { * Do not attempt to allocate anything but linear framebuffer memory * with single-plane RGB data. Allocation of other framebuffer * layouts requires dedicated ioctls in the respective DRM driver. + * There exists drivers exploiting this interface for framebuffers + * with modifiers other than DRM_FORMAT_MOD_LINEAR, but this is + * incorrect usage with undefined behavior, and should not be + * replicated. */ struct drm_mode_create_dumb { __u32 height; -- 2.52.0
