Re: [PATCH v6 1/2] ALSA: usb-audio: expose the Topping M62's analogue gains as mixer controls

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The patch uses crc16() but does not select CONFIG_CRC16 in Kconfig, causing a potential build failure.
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--- Patch [1]: [PATCH v6 1/2] ALSA: usb-audio: expose the Topping M62's analogue gains as mixer controls ---
commit 2f97c4794fd4611a2d19d7809d566fbe5f5f49ee
Author: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>

ALSA: usb-audio: expose the Topping M62's analogue gains as mixer controls

This commit adds mixer controls for the Topping M62 by exposing the analogue
input gains and output volumes over a vendor HID channel. It implements a
custom communication protocol in a new mixer_topping.c file to talk to the
device.

> diff --git a/sound/usb/mixer_topping.c b/sound/usb/mixer_topping.c
> new file mode 100644
> index 0000000000000..f8ddeafb02226
> --- /dev/null
> +++ b/sound/usb/mixer_topping.c
[ ... ]
> +static void topping_build(u8 *f, u8 target, u8 prop, s32 value)
> +{
> +	u16 crc;
> +
> +	f[0] = 0x22;
> +	f[1] = 0x33;
> +	f[2] = 0x20;
> +	f[3] = 0x01;
> +	f[4] = 0x01;
> +	f[5] = target;
> +	f[6] = prop;
> +	put_unaligned_be32(value, f + 7);
> +	crc = crc16(0xffff, f + 2, 9);

[Severity: Low]
Does SND_USB_AUDIO need to select CRC16 in sound/usb/Kconfig?

Since this new code uses crc16(), building the kernel with CONFIG_SND_USB_AUDIO
enabled but CONFIG_CRC16 disabled might fail during linking with an undefined
reference to crc16().

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Sashiko AI review · https://sashiko.dev/#/patchset/20260824223107.406504-1-mikhail.v.gavrilov@gmail.com?part=1