If the amp is still reporting FIRMWARE_MISSING after cs35l56_patch()
has completed it is helpful to log a warning.

After a complete firmware download the FIRMWARE_MISSING flag will be
clear. If this isn't the case, the driver should log a message to
report this.

The amp can produce basic audio output without firmware, as a fallback,
so this wasn't originally logged as a warning condition because the amp
is still in an operational state - just not with full functionality.
However, it was not at all obvious to an end user that anything is
unusual.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 include/sound/cs35l56.h           |  1 +
 sound/soc/codecs/cs35l56-shared.c | 17 +++++++++++++++++
 sound/soc/codecs/cs35l56.c        |  3 +++
 3 files changed, 21 insertions(+)

diff --git a/include/sound/cs35l56.h b/include/sound/cs35l56.h
index 883f6a7e50aa..5928af539c46 100644
--- a/include/sound/cs35l56.h
+++ b/include/sound/cs35l56.h
@@ -409,6 +409,7 @@ int cs35l56_cal_set_status_get(struct cs35l56_base *cs35l56_base,
 			       struct snd_ctl_elem_value *uvalue);
 int cs35l56_read_prot_status(struct cs35l56_base *cs35l56_base,
 			     bool *fw_missing, unsigned int *fw_version);
+void cs35l56_warn_if_firmware_missing(struct cs35l56_base *cs35l56_base);
 void cs35l56_log_tuning(struct cs35l56_base *cs35l56_base, struct cs_dsp *cs_dsp);
 int cs35l56_hw_init(struct cs35l56_base *cs35l56_base);
 int cs35l56_get_speaker_id(struct cs35l56_base *cs35l56_base);
diff --git a/sound/soc/codecs/cs35l56-shared.c b/sound/soc/codecs/cs35l56-shared.c
index 7424e1353062..60100c8f8c95 100644
--- a/sound/soc/codecs/cs35l56-shared.c
+++ b/sound/soc/codecs/cs35l56-shared.c
@@ -1337,6 +1337,23 @@ int cs35l56_read_prot_status(struct cs35l56_base *cs35l56_base,
 }
 EXPORT_SYMBOL_NS_GPL(cs35l56_read_prot_status, "SND_SOC_CS35L56_SHARED");
 
+void cs35l56_warn_if_firmware_missing(struct cs35l56_base *cs35l56_base)
+{
+	unsigned int firmware_version;
+	bool firmware_missing;
+	int ret;
+
+	ret = cs35l56_read_prot_status(cs35l56_base, &firmware_missing, &firmware_version);
+	if (ret)
+		return;
+
+	if (!firmware_missing)
+		return;
+
+	dev_warn(cs35l56_base->dev, "FIRMWARE_MISSING\n");
+}
+EXPORT_SYMBOL_NS_GPL(cs35l56_warn_if_firmware_missing, "SND_SOC_CS35L56_SHARED");
+
 void cs35l56_log_tuning(struct cs35l56_base *cs35l56_base, struct cs_dsp *cs_dsp)
 {
 	__be32 pid, sid, tid;
diff --git a/sound/soc/codecs/cs35l56.c b/sound/soc/codecs/cs35l56.c
index d8a3babce0f6..55b4d0d55712 100644
--- a/sound/soc/codecs/cs35l56.c
+++ b/sound/soc/codecs/cs35l56.c
@@ -823,6 +823,9 @@ static void cs35l56_patch(struct cs35l56_private *cs35l56, bool firmware_missing
 		goto err_unlock;
 	}
 
+	/* Check if the firmware is still reported missing */
+	cs35l56_warn_if_firmware_missing(&cs35l56->base);
+
 	regmap_clear_bits(cs35l56->base.regmap,
 			  cs35l56->base.fw_reg->prot_sts,
 			  CS35L56_FIRMWARE_MISSING);
-- 
2.43.0

On Fri, 28 Nov 2025 11:25:20 +0000, Richard Fitzgerald wrote:
> If the amp is still reporting FIRMWARE_MISSING after cs35l56_patch()
> has completed it is helpful to log a warning.
> 
> After a complete firmware download the FIRMWARE_MISSING flag will be
> clear. If this isn't the case, the driver should log a message to
> report this.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: cs35l56: Log a message if firmware is missing
      commit: 816c9cac35185aff33da1eb73cc974349623eb3a

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark