Re: [RFC V2 PATCH 00/11] Re: ALSA: usb-audio: Audient iD14 MkI vendor

[Will Porter <mrwillporter@gmail.com>]

Hi Christian,

Thanks for RFC V2, and for folding everything in so quickly.

On Mon, Nov 02, 2026 at 01:32:46AM +0100, Christian Ruppert wrote:
> Makes sense. Added to RFC V2 (in patch 10 where the cache is added).
> Please double-check if the logic reflects what you had in mind.

Yes, that is what I had in mind: a put of the cached value still
writes it, but returns 0, so alsactl restore sends no change events.
On an iD14 MkI, a put of the held value sent no change event on a
write-only switch, a volume or a matrix control. A put of a new value
on the write-only switch sent one.

One question on the same function. A FORCE_SET control without CACHE
now reads the device before each write; in RFC v1 the put skipped
that read. If the device refuses the read, the put fails before it
writes. No table uses FORCE_SET without CACHE today, so nothing
breaks now.

Should that combination work? If yes, the put could skip the read
when the control has no cache slot, as the diff below does. If not,
a comment or a check in snd_audient_add_ctrl() would say so, and you
can drop the diff.

> I don't think this is necessary as it should be rather obvious to
> everyone touching the driver that the u32 argument can't carry more
> than 4 bytes. Added a comment to the parameter definition.

Fine with me.

checkpatch --strict on the 11 patches gives no errors or warnings,
only CHECK-level style notes, mostly unneeded parentheses (04, 05,
07, 10) and alignment (01, 05). I'll leave those to your discretion.

iD14 patches on RFC V2

I rebased my iD14 patch series on RFC V2. Three of my patches are now
part of yours, so seven remain:

  1. a step size for integer controls
  2. enumerated controls
  3. a separate mixer map for the iD14 MkI
  4. iD14 MkI monitor and routing controls
  5. iD14 MkI mixer matrix
  6. iD14 MkI write-only controls
  7. the iD14 MkI FU 12 control

All 18 patches build one by one with W=1 without warnings.
On an iD14 MkI (7.2.11 stable), the controls passed the same read and
write checks as on RFC v1.

Next steps

As agreed, I'll send the final series: your 11 patches, then the
seven iD14 patches. Two questions first:

- Your four mixer_evo fixes ("ALSA: mixer_evo: minor fixes and tlv
  addition") are still open on Patchwork. Should they still go in
  separately, before this series? Then I'd base the final series on
  sound for-next once Takashi applies them. Or should I put them at
  the front of the final series?
- If the diff below looks right to you, shall I fold it into patch
  10 when I send, or would you prefer to take it into your own tree
  first?

Thanks,
Will

-- >8 --
From: Will Porter <mrwillporter@gmail.com>
Subject: [RFC PATCH] ALSA: mixer_audient: Skip the read for an uncached FORCE_SET put

A FORCE_SET put without a cache slot reads the device before the
write, and fails without writing if that read fails. Skip the read
in that case, as RFC v1 did. Puts on cached controls keep their
change reporting.

Also fix a typo in a comment and drop a blank line.

Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Will Porter <mrwillporter@gmail.com>
---
Proposed change to patch 10.

diff --git a/sound/usb/mixer_audient.c b/sound/usb/mixer_audient.c
index 483ab8f..33c2d1f 100644
--- a/sound/usb/mixer_audient.c
+++ b/sound/usb/mixer_audient.c
@@ -329,11 +329,12 @@ static int snd_audient_raw_set_one(struct usb_mixer_interface *const mixer,
 	int ret;
 	u32 val;
 
-	if (force) {
+	if (force ||
+	    (!slot && (ctype->flags & SND_AUDIENT_CTYPE_FLAGS_FORCE_SET))) {
 		val = !value;		/* just make it different */
 	} else {
 		ret = snd_audient_raw_get_one(mixer, ctype, slot, cidx, &val);
-		if (ret == -ENODATA)	/* FORCED_SET and not cached yet */
+		if (ret == -ENODATA)	/* FORCE_SET and not cached yet */
 			val = !value;	/* just make it different */
 		else if (ret < 0)
 			return ret;
@@ -352,7 +353,6 @@ static int snd_audient_raw_set_one(struct usb_mixer_interface *const mixer,
 			slot->value = value;
 			slot->valid = true;
 		}
-
 	}
 
 	return val != value;