chrontel: Temporary, Fix flicker on external display.
Its no longer true that the CRTC is active when backlight is set to
zero. Patch, takes this into account by treating this condition
similarly to the !'DPMS on' case.
This patch may need to be revisited when Nitrous goes live as well.
BUG=chromium-os:31650
TEST=manual,
1. crtc is off at launch of server
backlight-tool --set_brightness 0
/usr/bin/ch7036_monitor -v -d /dev/i2c-chrontel -g/sys/class/gpio/gpio207/value &
sleep 10 ; backlight-tool --set_brightness 100
Result,
external display is undriven until brightness is increased. Once
brightness is increased, external display show proper image
2. crtc is off after launch of server
/usr/bin/ch7036_monitor -v -d /dev/i2c-chrontel -g/sys/class/gpio/gpio207/value
backlight-tool --set_brightness 0
Result,
external display is driven initially. When brightness goes to zero
there is a brief flicker, then external display is undriven
I also just connected & disconnected several monitors while and cycled
their backlights.
Change-Id: I68389ee4ef4e44e747168ef0bd803ad429e1311e
Reviewed-on: https://gerrit.chromium.org/gerrit/25027
Tested-by: Todd Broch <tbroch@chromium.org>
Reviewed-by: Mark Hayter <mdhayter@chromium.org>
Commit-Ready: Todd Broch <tbroch@chromium.org>
2 files changed
