• Hans de Goede's avatar
    sunxi: video: Force h/vsync active high when using ext. vga dac on some boards · fb75d972
    Hans de Goede authored
    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: default avatarHans de Goede <hdegoede@redhat.com>
    Acked-by: default avatarIan Campbell <ijc@hellion.org.uk>
A13-OLinuXino_defconfig 689 Bytes