Wakeup the userspace poll on change of display status. The
userspace then may take action to change the
power/performance characteristics of the device.
Change-Id: I9bd11f3d895d3d83230104f5d8dcd1deeaa754cd
Signed-off-by: Amar Singhal <asinghal@codeaurora.org>
(cherry picked from commit 2fb0354486e2d7b8d73622cbdbb941748a921240)
Rather than signaling a full update of the display from userspace via a
console switch, this patch introduces 2 files int /sys/power,
wait_for_fb_sleep and wait_for_fb_wake. Reading these files will block
until the requested state has been entered. When a read from
wait_for_fb_sleep returns userspace should stop drawing. When
wait_for_fb_wake returns, it should do a full update. If either are called
when the fb driver is already in the requested state, they will return
immediately.
Signed-off-by: Rebecca Schultz <rschultz@google.com>
Signed-off-by: Arve Hjønnevåg <arve@android.com>
(cherry picked from commit 4b0ea27fc8202b21ce338c82b55eee9c281bd7da)
