Commit d04a0047 authored by Francesco Saverio Pavone's avatar Francesco Saverio Pavone Committed by Takashi Iwai
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ALSA: pcm_drm_eld: rate-limit ELD parsing errors 



Mirror of Mark Brown's ASoC: hdac_hdmi rate-limit patch (commit
[lkml.kernel.org/lkml/2025/6/13/1380]) for the generic snd_parse_eld()
helper used by ASoC hdmi-codec.

When a HDMI sink is disconnected (e.g. a board with two HDMI outputs and
only one cable), userspace audio servers like PipeWire keep probing the
disconnected card and trigger:

    HDMI: Unknown ELD version 0

at every probe — easily 30+ messages per burst on rk3588. The same
applies to malformed ELD (MNL out of range). Both conditions are
expected when no sink is attached; rate-limit the dev_info() so the
kernel ring buffer does not fill up.

Signed-off-by: default avatarFrancesco Saverio Pavone <pavone.lawyer@gmail.com>
Link: https://patch.msgid.link/20260516141244.21801-1-pavone.lawyer@gmail.com


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 0aacce7c

sound/core/pcm_drm_eld.c

+2 −2
Original line number Diff line number Diff line
@@ -334,7 +334,7 @@ int snd_parse_eld(struct device *dev, struct snd_parsed_hdmi_eld *e, 
	e->eld_ver = GRAB_BITS(buf, 0, 3, 5);

	if (e->eld_ver != ELD_VER_CEA_861D &&

	    e->eld_ver != ELD_VER_PARTIAL) {

		dev_info(dev, "HDMI: Unknown ELD version %d\n", e->eld_ver);

		dev_info_ratelimited(dev, "HDMI: Unknown ELD version %d\n", e->eld_ver);

		goto out_fail;

	}
@@ -357,7 +357,7 @@ int snd_parse_eld(struct device *dev, struct snd_parsed_hdmi_eld *e, 
	e->product_id	  = get_unaligned_le16(buf + 18);



	if (mnl > ELD_MAX_MNL) {

		dev_info(dev, "HDMI: MNL is reserved value %d\n", mnl);

		dev_info_ratelimited(dev, "HDMI: MNL is reserved value %d\n", mnl);

		goto out_fail;

	} else if (ELD_FIXED_BYTES + mnl > size) {

		dev_info(dev, "HDMI: out of range MNL %d\n", mnl);