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author | Hans de Goede <hdegoede@redhat.com> | 2015-01-25 15:33:07 +0100 |
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committer | Hans de Goede <hdegoede@redhat.com> | 2015-02-02 13:57:16 +0100 |
commit | fb75d972eaf5c887ada28e73d3e84d52931d4cb0 (patch) | |
tree | 1bd562e1ddadc7242ca3027a898c0f7461bd6501 /MAKEALL | |
parent | 8d0df9be927eff1be9aef29aa995f6b54900962e (diff) | |
download | u-boot-imx-fb75d972eaf5c887ada28e73d3e84d52931d4cb0.zip u-boot-imx-fb75d972eaf5c887ada28e73d3e84d52931d4cb0.tar.gz u-boot-imx-fb75d972eaf5c887ada28e73d3e84d52931d4cb0.tar.bz2 |
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 <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
Diffstat (limited to 'MAKEALL')
0 files changed, 0 insertions, 0 deletions