From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Thu, 22 Feb 2018 23:42:29 +0200
Subject: drm/uapi: The ctm matrix uses sign-magnitude representation
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Git-commit: 68824bb59d4892457401cdcd89e9bb3eef3ea780
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
The documentation for the ctm matrix suggests a two's complement
format, but at least the i915 implementation is using sign-magnitude
instead. And looks like malidp is doing the same. Change the docs
to match the current implementation, and change the type from __s64
to __u64 to drive the point home.
Cc: dri-devel@lists.freedesktop.org
Cc: Mihail Atanassov <mihail.atanassov@arm.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Cc: Mali DP Maintainers <malidp@foss.arm.com>
Cc: Johnson Lin <johnson.lin@intel.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180222214232.6064-1-ville.syrjala@linux.intel.com
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
include/uapi/drm/drm_mode.h | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -598,8 +598,11 @@ struct drm_mode_crtc_lut {
};
struct drm_color_ctm {
- /* Conversion matrix in S31.32 format. */
- __s64 matrix[9];
+ /*
+ * Conversion matrix in S31.32 sign-magnitude
+ * (not two's complement!) format.
+ */
+ __u64 matrix[9];
};
struct drm_color_lut {