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authorPaul Menzel <paulepanter@users.sourceforge.net>2009-06-16 15:34:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-16 19:48:00 -0700
commitb586640141ab5f4ab3b194419bc2c0f039e91dbc (patch)
tree2d9bc7d43ac48d879d7cad086aa1cf69ddb02b03 /drivers/video
parent491bcc9bf5d9a57f2d9cb3ce8ba0f6d48752c113 (diff)
downloadlinux-b586640141ab5f4ab3b194419bc2c0f039e91dbc.tar.bz2
intelfb: fix a bug when changing video timing
When changing video timing dynamically via fbset the screen sporadically is rendered black. With the attached fix which disables VCO prior to timing register change the problem disappears. I had a look at the Xserver register setup code. Here the VCO is disabled in the same way [1]. This patch is taken from vga-sync-field version 0.0.11 [2][3]. [1] http://cgit.freedesktop.org/xorg/driver/xf86-video-intel/tree/src/i830_= driver.c [2] http://lowbyte.de/vga-sync-fields/vga-sync-fields-0.0.11.tgz [3] http://easy-vdr.de/git?p=frc.git/.git;a=commit;h=dcc3b863e5a663652587619c357bd20075af6896 2587619c357bd20075af6896 Signed-off-by: Thomas Hilber <sparkie@lowbyte.de> Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/intelfb/intelfbdrv.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/video/intelfb/intelfbdrv.c b/drivers/video/intelfb/intelfbdrv.c
index ace14fe02fc4..0cafd642fbc0 100644
--- a/drivers/video/intelfb/intelfbdrv.c
+++ b/drivers/video/intelfb/intelfbdrv.c
@@ -1365,6 +1365,11 @@ static int intelfb_set_par(struct fb_info *info)
DBG_MSG("intelfb_set_par (%dx%d-%d)\n", info->var.xres,
info->var.yres, info->var.bits_per_pixel);
+ /*
+ * Disable VCO prior to timing register change.
+ */
+ OUTREG(DPLL_A, INREG(DPLL_A) & ~DPLL_VCO_ENABLE);
+
intelfb_blank(FB_BLANK_POWERDOWN, info);
if (ACCEL(dinfo, info))