[PATCH] drm/bridge: dw-hdmi-qp: Return -EOPNOTSUPP in HDMI audio functions

[Detlev Casanova]

-EOPNOTSUPP is not logged as an error by the ASoC subsystem, but -ENODEV
is.
It also better represents the situation: The operation is currently not
supported (because clocks are not enabled and tmds_char_rate is
unavailable), but the hardware is present.

Using -EOPNOTSUPP in the audio_prepare callback removes possible repeated
warning log lines when HDMI is not connected.

Returning -EOPNOTSUPP in the audio_enable callback is also needed as it
avoids logging 0-valued ELD errors.

When tmds_char_rate is available, the clocks are enabled and the
functions will keep returning 0 as before.

Signed-off-by: Detlev Casanova <detlev.casanova@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
index d649a1cf07f5..270c8c47d853 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
@@ -469,8 +469,10 @@ static int dw_hdmi_qp_audio_enable(struct drm_bridge *bridge,
 {
 	struct dw_hdmi_qp *hdmi = dw_hdmi_qp_from_bridge(bridge);
 
-	if (hdmi->tmds_char_rate)
-		dw_hdmi_qp_mod(hdmi, 0, AVP_DATAPATH_PACKET_AUDIO_SWDISABLE, GLOBAL_SWDISABLE);
+	if (!hdmi->tmds_char_rate)
+		return -EOPNOTSUPP;
+
+	dw_hdmi_qp_mod(hdmi, 0, AVP_DATAPATH_PACKET_AUDIO_SWDISABLE, GLOBAL_SWDISABLE);
 
 	return 0;
 }
@@ -484,7 +486,7 @@ static int dw_hdmi_qp_audio_prepare(struct drm_bridge *bridge,
 	bool ref2stream = false;
 
 	if (!hdmi->tmds_char_rate)
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	if (fmt->bit_clk_provider | fmt->frame_clk_provider) {
 		dev_err(hdmi->dev, "unsupported clock settings\n");

---
base-commit: 1a2ab0feaa23147e347b4d4cb79cb3fc392118eb
change-id: 20260519-fix-hdmi-audio-warnings-139062ec00b9

Best regards,
--  
Detlev Casanova <detlev.casanova@xxxxxxxxxxxxx>