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authorDaniel Vetter <daniel.vetter@ffwll.ch>2022-11-23 22:24:37 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2023-01-05 15:10:38 +0300
commitb357e7ac1b7349befaeded273b775c7af23a538b (patch)
tree6f7f0ccdb61a795ace4a13211d92c6ac25a66847 /include
parent8dd4e8c49efc5a7a3879e117e4aa58082734506e (diff)
downloadlinux-b357e7ac1b7349befaeded273b775c7af23a538b.tar.xz
drm/fourcc: Document open source user waiver
It's a bit a FAQ, and we really can't claim to be the authoritative source for allocating these numbers used in many standard extensions if we tell closed source or vendor stacks in general to go away. Iirc this was already clarified in some vulkan discussions, but I can't find that anywhere anymore. At least not in a public link. Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Alex Deucher <alexdeucher@gmail.com> Cc: Daniel Stone <daniel@fooishbar.org> Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> Cc: Jason Ekstrand <jason@jlekstrand.net> Cc: Neil Trevett <ntrevett@nvidia.com> Acked-by: Daniel Stone <daniels@collabora.com> Acked-by: Maxime Ripard <maxime@cerno.tech> Acked-by: David Airlie <airlied@gmail.com> Acked-by: Marek Olšák <maraeo@gmail.com> Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> Acked-by: Jason Ekstrand <jason.ekstrand@collabora.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221123192437.1065826-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'include')
-rw-r--r--include/uapi/drm/drm_fourcc.h12
1 files changed, 12 insertions, 0 deletions
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index bc056f2d537d..de703c6be969 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -88,6 +88,18 @@ extern "C" {
*
* The authoritative list of format modifier codes is found in
* `include/uapi/drm/drm_fourcc.h`
+ *
+ * Open Source User Waiver
+ * -----------------------
+ *
+ * Because this is the authoritative source for pixel formats and modifiers
+ * referenced by GL, Vulkan extensions and other standards and hence used both
+ * by open source and closed source driver stacks, the usual requirement for an
+ * upstream in-kernel or open source userspace user does not apply.
+ *
+ * To ensure, as much as feasible, compatibility across stacks and avoid
+ * confusion with incompatible enumerations stakeholders for all relevant driver
+ * stacks should approve additions.
*/
#define fourcc_code(a, b, c, d) ((__u32)(a) | ((__u32)(b) << 8) | \