[alsa-devel] [PATCH v4] ALSA: usb: Work around CM6631 sample rate change bug

[Clemens Ladisch]

Torstein Hegge wrote:
> +	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
> +				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
> +				   UAC2_CS_CONTROL_SAM_FREQ << 8,
> +				   snd_usb_ctrl_intf(chip) | (clock << 8),
> +				   data, sizeof(data))) < 0) {
> +		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
> +			   dev->devnum, iface, fmt->altsetting);
> +		return err;
> +	}

This code requires that all devices allow reading the sample rate.

When you cannot read the current rate, just assume it needs to be set.


Regards,
Clemens