| Message ID | 1323174425-24038-1-git-send-email-LW@KARO-electronics.de |
|---|---|
| State | New |
| Headers | show |
Hi, Lothar Waßmann writes: > 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. > > 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 d837d63..03cb95a 100644 > --- a/drivers/video/mxsfb.c > +++ b/drivers/video/mxsfb.c > @@ -366,7 +366,8 @@ 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(host->clk); > > -- > 1.5.6.5 > Ping. Any comments on this? Lothar Waßmann
Hi Lothar, > Hi, > > Lothar Waßmann writes: >> 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. >> >> 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 d837d63..03cb95a 100644 >> --- a/drivers/video/mxsfb.c >> +++ b/drivers/video/mxsfb.c >> @@ -366,7 +366,8 @@ 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(host->clk); >> >> -- >> 1.5.6.5 >> > Ping. Any comments on this? > > > Lothar Waßmann I've encountered this problem to, and i can confirm your patch fixed it. The VDCTRL4 register has no CLR feature. Regards,
diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c index d837d63..03cb95a 100644 --- a/drivers/video/mxsfb.c +++ b/drivers/video/mxsfb.c @@ -366,7 +366,8 @@ 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(host->clk);
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. Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> --- drivers/video/mxsfb.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)