Re: [PATCH 0/3] ALSA: scarlett2: Fix 2i2 Gen 4 direct monitor on firmware 2417

[Takashi Iwai <tiwai@suse.de>]

On Sat, 25 Apr 2026 23:07:30 +0200,
Geoffrey D. Bennett wrote:
> 
> Hi Takashi,
> 
> Firmware 2417 for the Scarlett 4th Gen 2i2 moved the direct monitor
> gain parameters, breaking that control's functionality.
> 
> The driver already has per-device scarlett2_config_set tables
> describing each parameter's offset, but only one table per device, so
> there was no way to express "this offset changed at firmware version
> N". This series adds that capability and uses it to fix the 2i2 Gen 4.
> 
> Patches
> -------
> 
> 1/3: Replace the device info's single config_set pointer with a
> config_sets array of {from_firmware_version, config_set} entries, and
> resolve the running config_set at probe time once the firmware version
> has been read. Each device gets a single entry matching its previous
> min_firmware_version (or 0), so this is a no-op preparation step.
> 
> 2/3: Drop the now-redundant min_firmware_version field from
> scarlett2_device_info; config_sets[0].from_firmware_version carries
> the same meaning. No functional change.
> 
> 3/3: Add a second 2i2 Gen 4 config_set with DIRECT_MONITOR_GAIN at the
> new offset, gated on firmware >= 2417. All other offsets are
> unchanged.
> 
> Patch 1 is a prerequisite for patch 3. Patch 2 isn't a strict
> dependency, but it removes a now-redundant field, so patch 3's Cc:
> stable trailer names both 1 and 2 as prereqs by subject (please
> substitute SHAs at apply time). Patch 2 can be dropped from the stable
> backport if you'd prefer.
> 
> Tested
> ------
> 
> Verified on a Scarlett 2i2 4th Gen by writing to Monitor 1 Mix A Input
> 01 and observing with usbmon:
> 
> - Firmware 2128, patched driver:   write targets offset 0x2A0
> - Firmware 2417, patched driver:   write targets offset 0x2A4
> - Firmware 2417, unpatched driver: write targets offset 0x2A0 (bug)
> 
> Regards,
> Geoffrey
> 
> Geoffrey D. Bennett (3):
>   ALSA: scarlett2: Allow selecting config_set by firmware version
>   ALSA: scarlett2: Fold min_firmware_version into config_sets
>   ALSA: scarlett2: Update offsets for 2i2 Gen 4 firmware 2417

Applied all to for-next branch now.  Thanks.


Takashi