drm/i915: DisplayPort hot remove notification to audio driver

On DP monitor hot remove, clear DP_AUDIO_OUTPUT_ENABLE accordingly,
so that the audio driver will receive hot plug events and take action
to refresh its device state and ELD contents.

Note that the DP_AUDIO_OUTPUT_ENABLE bit may be enabled or disabled
only when the link training is complete and set to "Normal".

Tested OK for both hot plug/remove and DPMS on/off.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 92b041b66e49..db3b461ad412 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1926,6 +1926,7 @@ intel_dp_link_down(struct intel_dp *intel_dp)
                         intel_wait_for_vblank(dev, to_intel_crtc(crtc)->pipe);
         }
 
+        DP &= ~DP_AUDIO_OUTPUT_ENABLE;
         I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
         POSTING_READ(intel_dp->output_reg);
         msleep(intel_dp->panel_power_down_delay);