UPSTREAM: drm/rockchip: cdn-dp: retry to check sink count

Sometimes the Dock is disconnected, but cdn_dp_encoder_disable is not
triggered by DRM. For example, unplug the Dock in console mode, and
re-plug it again, the cdn_dp_event_work will try to get the sink count
of Dock, since the DP is still active. But the Dock has been powered
down, it need re-power on, and wait for a while until it is ready to
DPCD communication.

BUG=chrome-os-partner:61939
TEST=connect HDMI Dock in normal world, then swich to console mode,
Unplug HDMI Dock, then re-plug it in same Type-C port, swich back to
normal world, HDMI can display.

(cherry picked from git.kernel.org next/linux-next.git master
 commit 13e0e2069401f2692cf25eb3c7f61137b5f9902d)
Change-Id: I59c17a7ce41d5697b33195894eaf4bb49ac85171
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/430553
Commit-Ready: Guenter Roeck <groeck@chromium.org>
Tested-by: Jongpil Jung <jongpil19.jung@samsung.com>
Reviewed-by: St├ęphane Marchesin <marcheu@chromium.org>
2 files changed