viafb: correct sync polarity for OLPC DCON
authorDaniel Drake <dsd@laptop.org>
Mon, 21 Nov 2011 15:05:56 +0000 (15:05 +0000)
committerGreg Kroah-Hartman <gregkh@suse.de>
Fri, 9 Dec 2011 16:54:10 +0000 (08:54 -0800)
commitdf01c1efffdaf26ef874f96986a64776c170b024
treee17f5c01d7b9e6b1d5db52564ec50a7aba4b9b09
parentcbd00285bbef94804213974a5fd084c3f7197ec6
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>
drivers/video/via/share.h