[PATCH] drm/radeon: Fix spurious unplug event on radeon HDMI

[Steven 'Steve' Kendall]

On several HP models (tested on HP 3125 and HP Probook 455 G2),
spurious unplug events are emitted upon login on Chrome OS.
This is likely due to the way Chrome OS restarts graphics
upon login, so it's possible it's an issue on other
distributions but not as common, though I haven't
reproduced the issue elsewhere.
Use logic from an earlier version of the merged change
(see link below) which iterates over connectors and finds
matching encoders, rather than the other way around.
Also fixes an issue with screen mirroring on Chrome OS.
I've deployed this patch on Fedora and did not observe
any regression on these devices.

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1569#note_1603002
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/3771
Fixes: 20ea34710f7b ("drm/radeon: Add HD-audio component notifier support (v6)")
Signed-off-by: Steven 'Steve' Kendall <skend at chromium.org>
---
 drivers/gpu/drm/radeon/radeon_audio.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_audio.c b/drivers/gpu/drm/radeon/radeon_audio.c
index 47aa06a9a942..5b69cc8011b4 100644
--- a/drivers/gpu/drm/radeon/radeon_audio.c
+++ b/drivers/gpu/drm/radeon/radeon_audio.c
@@ -760,16 +760,20 @@ static int radeon_audio_component_get_eld(struct device *kdev, int port,
 	if (!rdev->audio.enabled || !rdev->mode_info.mode_config_initialized)
 		return 0;
 
-	list_for_each_entry(encoder, &rdev_to_drm(rdev)->mode_config.encoder_list, head) {
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		const struct drm_connector_helper_funcs *connector_funcs =
+				connector->helper_private;
+		encoder = connector_funcs->best_encoder(connector);
+
+		if (!encoder)
+			continue;
+
 		if (!radeon_encoder_is_digital(encoder))
 			continue;
 		radeon_encoder = to_radeon_encoder(encoder);
 		dig = radeon_encoder->enc_priv;
 		if (!dig->pin || dig->pin->id != port)
 			continue;
-		connector = radeon_get_connector_for_encoder(encoder);
-		if (!connector)
-			continue;
 		*enabled = true;
 		ret = drm_eld_size(connector->eld);
 		memcpy(buf, connector->eld, min(max_bytes, ret));

---
base-commit: 2d5404caa8c7bb5c4e0435f94b28834ae5456623
change-id: 20241115-hdmi-audio-radeon-connectors-f8ffac989b0d

Best regards,
-- 
Steven 'Steve' Kendall <skend at chromium.org>