drm/gamma: Clarify gamma lut uapi
authorDaniel Vetter <daniel.vetter@ffwll.ch>
Fri, 29 Mar 2019 09:20:27 +0000 (10:20 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Wed, 3 Apr 2019 16:26:03 +0000 (18:26 +0200)
commit1fa6fa1cad3aff9924aaf74f21ab80bd67a96ef4
treeae4284dde7cd9bbdab697ba90792033a2f4fd1ff
parent6e3f17ee73f7e3c2ef0e2c8fd8624b2ece8ef2c9
drm/gamma: Clarify gamma lut uapi

Interpreting it as a 0.16 fixed point means we can't accurately
represent 1.0. Which is one of the values we really should be able to
represent.

Since most (all?) luts have lower precision this will only affect
rounding of 0xffff.

Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: "Kumar, Kiran S" <kiran.s.kumar@intel.com>
Cc: Kausal Malladi <kausalmalladi@gmail.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Rob Bradford <robert.bradford@intel.com>
Cc: Daniel Stone <daniels@collabora.com>
Cc: Stefan Schake <stschake@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: James (Qian) Wang <james.qian.wang@arm.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Mali DP Maintainers <malidp@foss.arm.com>
Cc: CK Hu <ck.hu@mediatek.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Yannick Fertre <yannick.fertre@st.com>
Cc: Philippe Cornu <philippe.cornu@st.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Philippe Cornu <philippe.cornu@st.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190329092027.3430-1-daniel.vetter@ffwll.ch
include/uapi/drm/drm_mode.h