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* [BUGFIX PATCH] video: mxsfb: fix crash when unblanking the display
@ 2012-11-22 12:49 Lothar Waßmann
  2012-11-22 12:49 ` [PATCH] video: mxsfb: fix typo: 'FAILING' instead of 'FALLING' Lothar Waßmann
  2012-11-29 11:55 ` [BUGFIX PATCH] video: mxsfb: fix crash when unblanking the display Lothar Waßmann
  0 siblings, 2 replies; 8+ messages in thread
From: Lothar Waßmann @ 2012-11-22 12:49 UTC (permalink / raw)
  To: linux-arm-kernel

The VDCTRL4 register does not provide the MXS SET/CLR/TOGGLE feature.
The write in mxsfb_disable_controller() sets the data_cnt for the LCD
DMA to 0 which obviously means the max. count for the LCD DMA and
leads to overwriting arbitrary memory when the display is unblanked.

Note: I already sent this patch in December 2011 but noone picked it up obviously.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
---
 drivers/video/mxsfb.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
index 49619b4..f2a49ef 100644
--- a/drivers/video/mxsfb.c
+++ b/drivers/video/mxsfb.c
@@ -369,7 +369,8 @@ static void mxsfb_disable_controller(struct fb_info *fb_info)
 		loop--;
 	}
 
-	writel(VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4 + REG_CLR);
+	reg = readl(host->base + LCDC_VDCTRL4);
+	writel(reg & ~VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4);
 
 	clk_disable_unprepare(host->clk);
 
-- 
1.7.2.5


^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2013-01-04  7:42 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-11-22 12:49 [BUGFIX PATCH] video: mxsfb: fix crash when unblanking the display Lothar Waßmann
2012-11-22 12:49 ` [PATCH] video: mxsfb: fix typo: 'FAILING' instead of 'FALLING' Lothar Waßmann
2012-11-29 11:59   ` Lothar Waßmann
2012-11-29 13:42     ` Juergen Beisert
2012-11-29 11:55 ` [BUGFIX PATCH] video: mxsfb: fix crash when unblanking the display Lothar Waßmann
2012-11-29 13:50   ` Juergen Beisert
2013-01-04  7:08   ` Lauri Hintsala
2013-01-04  7:42     ` Shawn Guo

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