viafb: correct sync polarity for OLPC DCON

commit a32839696a8eef813a1aff604fbad9a32dff6c95 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
parent ff17063daf
commit 47b52de3fa

View File

@@ -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