Commit 6833d26ef8 ("drm: tda998x: Fix EDID read timeout on HDMI
connect") used a weak scheme to try and delay reading EDID on a HDMI
connect event. It is weak because delaying the notification of a
hotplug event does not stop userspace from trying to read the EDID
within the 100ms delay.
The solution provided here solves this issue:
* When a HDMI connection event is detected, mark a blocking flag for
EDID reads, and start a timer for the delay.
* If an EDID read is attempted, and the blocking flag is set, wait
for the blocking flag to clear.
* When the timer expires, clear the blocking flag and wake any thread
waiting for the EDID read.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
0fc6f44d96