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viafb: correct sync polarity for OLPC DCON

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commit a32839696a upstream.

While the OLPC display appears to be able to handle either positive
or negative sync, the Display Controller only recognises positive sync.

This brings viafb (for XO-1.5) in line with lxfb (for XO-1) and
fixes a recent regression where the XO-1.5 DCON could no longer be
frozen. Thanks to Florian Tobias Schandinat for helping identify
the fix.

Test case: from a vt,
	echo 1 > /sys/devices/platform/dcon/freeze
should cause the current screen contents to freeze, rather than garbage being
displayed.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Daniel Drake 2011-11-21 15:05:56 +00:00 • committed by Greg Kroah-Hartman
commit 47b52de3fa
1 changed files with 2 additions and 2 deletions
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4
drivers/video/via/share.h
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@ -557,8 +557,8 @@
#define M1200X720_R60_VSP POSITIVE
/* 1200x900@60 Sync Polarity (DCON) */
#define M1200X900_R60_HSP NEGATIVE
#define M1200X900_R60_VSP NEGATIVE
#define M1200X900_R60_HSP POSITIVE
#define M1200X900_R60_VSP POSITIVE
/* 1280x600@60 Sync Polarity (GTF Mode) */
#define M1280x600_R60_HSP NEGATIVE