By default, HPD was disabled on SN65DSI86 bridge. When the driver was
added (commit "a095f15c00e27"), the HPD_DISABLE bit was set in pre-enable
call which was moved to other function calls subsequently.
Later on, commit "c312b0df3b13" added detect utility for DP mode. But with
HPD_DISABLE bit set, all the HPD events are disabled[0] and the debounced
state always return 1 (always connected state).
Set HPD_DISABLE bit conditionally based on display sink's connector type.
Since the HPD_STATE is reflected correctly only after waiting for debounce
time (~100-400ms) and adding this delay in detect() is not feasible
owing to the performace impact (glitches and frame drop), remove runtime
calls in detect() and add hpd_enable()/disable() bridge hooks with runtime
calls, to detect hpd properly without any delay.
[0]: <https://www.ti.com/lit/gpn/SN65DSI86> (Pg. 32)
Fixes: c312b0df3b ("drm/bridge: ti-sn65dsi86: Implement bridge connector operations for DP")
Cc: Max Krummenacher <max.krummenacher@toradex.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Ernest Van Hoecke <ernest.vanhoecke@toradex.com>
Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250624044835.165708-1-j-choudhary@ti.com
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