linux-kernel - [PATCH] ASoC: hdac_hdmi: Rate limit logging on connection and disconnection

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Message-Id: <20250613-asoc-hdmi-eld-logging-v1-1-76d64154d969@kernel.org>
Date: Fri, 13 Jun 2025 17:41:04 +0100
From: Mark Brown <broonie@...nel.org>
To: Liam Girdwood <lgirdwood@...il.com>, Jaroslav Kysela <perex@...ex.cz>, 
 Takashi Iwai <tiwai@...e.com>
Cc: Dmitry Baryshkov <lumag@...nel.org>, linux-sound@...r.kernel.org, 
 linux-kernel@...r.kernel.org, Mark Brown <broonie@...nel.org>
Subject: [PATCH] ASoC: hdac_hdmi: Rate limit logging on connection and
 disconnection

We currently log parse failures for ELD data and some disconnection events
as errors without rate limiting. These log messages can be triggered very
frequently in some situations, especially ELD parsing when there is nothing
connected to a HDMI port which will generate:

hdmi-audio-codec hdmi-audio-codec.1.auto: HDMI: Unknown ELD version 0

While there's doubtless work that could be done on reducing the number of
connection notification callbacks it's possible these may be legitimately
generated by poor quality physical connections so let's use rate limiting
to mitigate the log spam for the parse errors and lower the severity for
disconnect logging to debug level.

Signed-off-by: Mark Brown <broonie@...nel.org>
---
 sound/soc/codecs/hdac_hdmi.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/sound/soc/codecs/hdac_hdmi.c b/sound/soc/codecs/hdac_hdmi.c
index 1139a2754ca3..056d98154682 100644
--- a/sound/soc/codecs/hdac_hdmi.c
+++ b/sound/soc/codecs/hdac_hdmi.c
@@ -1232,7 +1232,8 @@ static int hdac_hdmi_parse_eld(struct hdac_device *hdev,
 						>> DRM_ELD_VER_SHIFT;
 
 	if (ver != ELD_VER_CEA_861D && ver != ELD_VER_PARTIAL) {
-		dev_err(&hdev->dev, "HDMI: Unknown ELD version %d\n", ver);
+		dev_err_ratelimited(&hdev->dev,
+				    "HDMI: Unknown ELD version %d\n", ver);
 		return -EINVAL;
 	}
 
@@ -1240,7 +1241,8 @@ static int hdac_hdmi_parse_eld(struct hdac_device *hdev,
 		DRM_ELD_MNL_MASK) >> DRM_ELD_MNL_SHIFT;
 
 	if (mnl > ELD_MAX_MNL) {
-		dev_err(&hdev->dev, "HDMI: MNL Invalid %d\n", mnl);
+		dev_err_ratelimited(&hdev->dev,
+				    "HDMI: MNL Invalid %d\n", mnl);
 		return -EINVAL;
 	}
 
@@ -1299,8 +1301,8 @@ static void hdac_hdmi_present_sense(struct hdac_hdmi_pin *pin,
 
 	if (!port->eld.monitor_present || !port->eld.eld_valid) {
 
-		dev_err(&hdev->dev, "%s: disconnect for pin:port %d:%d\n",
-						__func__, pin->nid, port->id);
+		dev_dbg(&hdev->dev, "%s: disconnect for pin:port %d:%d\n",
+			__func__, pin->nid, port->id);
 
 		/*
 		 * PCMs are not registered during device probe, so don't

---
base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
change-id: 20250613-asoc-hdmi-eld-logging-11bf756cff6d

Best regards,
-- 
Mark Brown <broonie@...nel.org>