Bug 16651 - Output of drm_cvt_mode function incorrect for reduced blanking modes
Summary: Output of drm_cvt_mode function incorrect for reduced blanking modes
Status: RESOLVED CODE_FIX
Alias: None
Product: Drivers
Classification: Unclassified
Component: Video(DRI - non Intel) (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: drivers_video-dri
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-08-21 02:36 UTC by Adam Serbinski
Modified: 2010-08-24 12:25 UTC (History)
1 user (show)

See Also:
Kernel Version: 2.6.35
Subsystem:
Regression: No
Bisected commit-id:

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Description Adam Serbinski 2010-08-21 02:36:51 UTC 
drivers/gpu/drm/drm_modes.c
function drm_cvt_mode

When parameter "reduced" is set to TRUE, the hsync_start and hsync_end values calculated are... wrong, and the vsync_start and vsync_end values aren't calculated at all.

Output from command "cvt -r 1920 1200":
# 1920x1200 59.95 Hz (CVT 2.30MA-R) hsync: 74.04 kHz; pclk: 154.00 MHz
Modeline "1920x1200R" 154.00 1920 1968 2000 2080 1200 1203 1209 1235 +hsync -vsync

The values generated by drm_cvt_mode(dev,1920,1200,60,true,false,false) are:
154.00 1920 32 32 2080 1200 0 0 1235 +hsync -vsync
Comment 1 Adam Jackson 2010-08-23 14:32:25 UTC 
Try this patch:

http://lists.freedesktop.org/archives/dri-devel/2010-August/003223.html
Comment 2 Adam Serbinski 2010-08-24 12:25:43 UTC 
That did the job.

Thank you.
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