[PATCH 2/2] ASoC: cs35l56: Stop creating ALSA controls for firmware coefficients

[PATCH 2/2] ASoC: cs35l56: Stop creating ALSA controls for firmware coefficients

[Simon Trimmer]

A number of laptops have gone to market with old firmware versions that
export controls that have since been hidden, but we can't just install a
newer firmware because the firmware for each product is customized and
qualified by the OEM. The issue is that alsactl save and restore has no
idea what controls are good to persist which can lead to
misconfiguration.

There is no reason that the UCM or user should need to interact with any
of the ALSA controls for the firmware coefficients so they can be
removed entirely.

Fixes: e49611252900 ("ASoC: cs35l56: Add driver for Cirrus Logic CS35L56")
Signed-off-by: Simon Trimmer <simont@opensource.cirrus.com>
---
 sound/soc/codecs/cs35l56.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/sound/soc/codecs/cs35l56.c b/sound/soc/codecs/cs35l56.c
index 84c34f5b1a51..757ade6373ed 100644
--- a/sound/soc/codecs/cs35l56.c
+++ b/sound/soc/codecs/cs35l56.c
@@ -1095,6 +1095,11 @@ int cs35l56_system_resume(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(cs35l56_system_resume);
 
+static int cs35l56_control_add_nop(struct wm_adsp *dsp, struct cs_dsp_coeff_ctl *cs_ctl)
+{
+	return 0;
+}
+
 static int cs35l56_dsp_init(struct cs35l56_private *cs35l56)
 {
 	struct wm_adsp *dsp;
@@ -1117,6 +1122,12 @@ static int cs35l56_dsp_init(struct cs35l56_private *cs35l56)
 	dsp->fw = 12;
 	dsp->wmfw_optional = true;
 
+	/*
+	 * None of the firmware controls need to be exported so add a no-op
+	 * callback that suppresses creating an ALSA control.
+	 */
+	dsp->control_add = &cs35l56_control_add_nop;
+
 	dev_dbg(cs35l56->base.dev, "DSP system name: '%s'\n", dsp->system_name);
 
 	ret = wm_halo_init(dsp);
-- 
2.43.0

Re: [PATCH 0/2] ASoC: Extend wm_adsp so cs35l56 can suppress controls

[Mark Brown]

On Mon, 05 Aug 2024 10:27:19 +0000, Simon Trimmer wrote:
> This pair of patches extend wm_adsp to add a callback that can be used
> to control whether ALSA controls are added and then tweak cs35l56 to use
> it to suppress controls made from firmware coefficients.
> 
> Simon Trimmer (2):
>   ASoC: wm_adsp: Add control_add callback and export
>     wm_adsp_control_add()
>   ASoC: cs35l56: Stop creating ALSA controls for firmware coefficients
> 
> [...]

Applied to

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

Thanks!

[1/2] ASoC: wm_adsp: Add control_add callback and export wm_adsp_control_add()
      commit: 45b4acab4cac79503663f0a4be9eb3752db04d4b
[2/2] ASoC: cs35l56: Stop creating ALSA controls for firmware coefficients
      commit: 2c3640b82213cf2beb7c1cc3cfce2ecf5349b0de

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