[PATCH 1/1] video: mxsfb: fix pixel clock polarity

DISPLAY_FLAGS_PIXDATA_NEGEDGE means the controller drives the data on pixel clocks falling edge. That is DOTCLK_POL=0 (default) not 1.
The same change has been made on the Linux's driver: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/dr...
Signed-off-by: Sébastien Szymanski sebastien.szymanski@armadeus.com --- drivers/video/mxsfb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c index 98d2965711..7aeea4b23f 100644 --- a/drivers/video/mxsfb.c +++ b/drivers/video/mxsfb.c @@ -161,7 +161,7 @@ static void mxs_lcd_init(struct udevice *dev, u32 fb_addr, vdctrl0 |= LCDIF_VDCTRL0_HSYNC_POL; if(flags & DISPLAY_FLAGS_VSYNC_HIGH) vdctrl0 |= LCDIF_VDCTRL0_VSYNC_POL; - if(flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE) + if(flags & DISPLAY_FLAGS_PIXDATA_POSEDGE) vdctrl0 |= LCDIF_VDCTRL0_DOTCLK_POL; if(flags & DISPLAY_FLAGS_DE_HIGH) vdctrl0 |= LCDIF_VDCTRL0_ENABLE_POL;

Hi Sébastien,
[Adding Anatolij]
On Fri, Nov 26, 2021 at 1:49 PM Sébastien Szymanski sebastien.szymanski@armadeus.com wrote:
DISPLAY_FLAGS_PIXDATA_NEGEDGE means the controller drives the data on pixel clocks falling edge. That is DOTCLK_POL=0 (default) not 1.
The same change has been made on the Linux's driver: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/dr...
Signed-off-by: Sébastien Szymanski sebastien.szymanski@armadeus.com
Reviewed-by: Fabio Estevam festevam@gmail.com

Hi Sébastien,
On Fri, 26 Nov 2021 15:48:27 +0100 Sébastien Szymanski sebastien.szymanski@armadeus.com wrote:
DISPLAY_FLAGS_PIXDATA_NEGEDGE means the controller drives the data on pixel clocks falling edge. That is DOTCLK_POL=0 (default) not 1.
I wanted to apply this patch for release, but testing on i.MX6UL 14x14 EVK board shows that there is display flickering. So it seems wrong for the display used on the EVK board.
-- Anatolij
participants (3)
-
Anatolij Gustschin
-
Fabio Estevam
-
Sébastien Szymanski