Hi Lothar,
Lothar Waßmann wrote:
quoted
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.
Overwriting? It should be a reading DMA unit, shouldn't it?
quoted
Note: I already sent this patch in December 2011 but noone picked it up
obviously.
Signed-off-by: Lothar Waßmann <redacted>
---
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
ping?
I'm not sure if the missing SET/CLR feature for this register is a typo in the
i.MX23/i.MX28 data sheets or if it is intended. Lets assume its the truth
what they have written:
Acked-by: Juergen Beisert <redacted>
Regards,
Juergen
--
Pengutronix e.K. | Juergen Beisert |
Linux Solutions for Science and Industry | http://www.pengutronix.de/ |