From dfc906daeec03b3f2d306ae260d398d97ba232c5 Mon Sep 17 00:00:00 2001 From: Martin Decky Date: Sun, 13 Feb 2011 19:28:40 +0000 Subject: [PATCH] video: Fix EDID macros H_SYNC_WIDTH and H_SYNC_OFFSET The macros for getting the values for horizontal sync width and offset do not respect the EDID specification. Both these values are 10 bit values according to [1], not 6 bit values. The lower 8 bits are stored in byte 8 and byte 9 of the DTD respectively, while two additional bits for each value are stored in byte 11. The original macros just slammed the bits together. Although the original macros usually worked fine because the higher two bits are rarely used, it can cause severe problems on plasma panels running at 1920x1080 @ 50 Hz with drivers that rely on the correct parsing of the EDID data by fbmon.c (e.g. udlfb). The patch should apply cleanly to both the fbdev-2.6.git branch and linux-next.git branch. [1] VESA Enhanced Extended Display Identification Data Standard, Release A, Revision 2, page 34, notes 7 & 8, VESA, Sep 2006 Signed-off-by: Martin Decky Signed-off-by: Paul Mundt --- drivers/video/edid.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/video/edid.h b/drivers/video/edid.h index bd89fb3be8c2..d03a232d90b2 100644 --- a/drivers/video/edid.h +++ b/drivers/video/edid.h @@ -101,8 +101,8 @@ #define V_SYNC_WIDTH COMBINE_HI_4LO( V_SYNC_WIDTH_HI, V_SYNC_WIDTH_LO ) #define V_SYNC_OFFSET COMBINE_HI_4LO( V_SYNC_OFFSET_HI, V_SYNC_OFFSET_LO ) -#define H_SYNC_WIDTH COMBINE_HI_4LO( H_SYNC_WIDTH_HI, H_SYNC_WIDTH_LO ) -#define H_SYNC_OFFSET COMBINE_HI_4LO( H_SYNC_OFFSET_HI, H_SYNC_OFFSET_LO ) +#define H_SYNC_WIDTH COMBINE_HI_8LO( H_SYNC_WIDTH_HI, H_SYNC_WIDTH_LO ) +#define H_SYNC_OFFSET COMBINE_HI_8LO( H_SYNC_OFFSET_HI, H_SYNC_OFFSET_LO ) #define H_SIZE_LO (unsigned)block[ 12 ] #define V_SIZE_LO (unsigned)block[ 13 ] -- GitLab