From fb75d972eaf5c887ada28e73d3e84d52931d4cb0 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sun, 25 Jan 2015 15:33:07 +0100 Subject: sunxi: video: Force h/vsync active high when using ext. vga dac on some boards On both my A13-OLinuxIno and my A13-OLinuxIno-Micro, the vga output gives an unstable image when active low v or hsync is used. The problem seems to be specific to the OLinuxIno A13 (normal & micro) boards. I've just looked up the schematics and they use an opendrain driver for the vga sync lines, and with sync pulses it is the logical high->low edge of the pulse which counts for the timing, which with an active low sync is being driven by the pull-up, and that simply seems to not drive it hard enough to get a stable image. So force v and hsync active high on these boards. independent of what the modeline says. This fixes the unstable image. Signed-off-by: Hans de Goede Acked-by: Ian Campbell --- configs/A13-OLinuXinoM_defconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'configs/A13-OLinuXinoM_defconfig') diff --git a/configs/A13-OLinuXinoM_defconfig b/configs/A13-OLinuXinoM_defconfig index 1c3fc3a3e9..a04f2b3362 100644 --- a/configs/A13-OLinuXinoM_defconfig +++ b/configs/A13-OLinuXinoM_defconfig @@ -4,6 +4,7 @@ CONFIG_FDTFILE="sun5i-a13-olinuxino-micro.dtb" CONFIG_USB1_VBUS_PIN="PG11" CONFIG_VIDEO_HDMI=n CONFIG_VIDEO_VGA_VIA_LCD=y +CONFIG_VIDEO_VGA_VIA_LCD_FORCE_SYNC_ACTIVE_HIGH=y # For use with the Olimex 7" LCD module, adjust timings for other displays # Set video-mode=sunxi:800x600-24@60,monitor=lcd in the env. to enable CONFIG_VIDEO_LCD_MODE="x:800,y:480,depth:18,pclk_khz:33000,le:16,ri:209,up:22,lo:22,hs:30,vs:1,sync:3,vmode:0" -- cgit v1.2.1