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authorChristoph Niedermaier2018-11-05 09:48:34 +0100
committerJonathan Corbet2018-11-06 15:36:18 +0100
commitd2f112a5681078aa2150f218074f76617fea4d74 (patch)
tree3df1cfe1b211827eb77446a0f9b7e9673b26c554 /Documentation/EDID/HOWTO.txt
parentLinux 4.20-rc1 (diff)
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Docs/EDID: Fixed erroneous bits of XOFFSET, XPULSE, YOFFSET and YPULSE
The problem was found when EDID data sets for displays other than the provided samples were generated. The patch has no effect on the provided samples that still match the data used in drivers/gpu/drm/drm_edid_load.c. The provided samples use small values for XOFFSET, XPULSE, YOFFSET and YPULSE, where the error doesn't occur. This fix corrects the use of that values in case of high values, because the most significant bits were treated incorrectly. So in edid.S msbs4 should use bit 8 and 9 of XOFFSET and XPULS. For YOFFSET and YPULSE msbs4 should use bit 4 and 5. lsbs2 was introduced for a better overview, without functional change. Removing also the useless value 63 of all files, because it is added in the *.S description files and then it is subtracted in edid.S. Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.de> Reviewed-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/EDID/HOWTO.txt')
-rw-r--r--Documentation/EDID/HOWTO.txt4
1 files changed, 2 insertions, 2 deletions
diff --git a/Documentation/EDID/HOWTO.txt b/Documentation/EDID/HOWTO.txt
index 835db332289b..7d05a7d30a79 100644
--- a/Documentation/EDID/HOWTO.txt
+++ b/Documentation/EDID/HOWTO.txt
@@ -45,8 +45,8 @@ EDID:
#define YPIX vdisp
#define YBLANK vtotal-vdisp
-#define YOFFSET (63+(vsyncstart-vdisp))
-#define YPULSE (63+(vsyncend-vsyncstart))
+#define YOFFSET vsyncstart-vdisp
+#define YPULSE vsyncend-vsyncstart
The CRC value in the last line
#define CRC 0x55