On 06.06.21 16:16, Geoffrey D. Bennett wrote:
> Add support for reading the mixer volumes from the hardware when the
> driver is initialising. Previously these ALSA volume controls were
> initialised to zero instead of being initialised to match the hardware
> state.
>
> Fixes: 9e4d5c1be21f ("ALSA: usb-audio: Scarlett Gen 2 mixer interface")
> Suggested-by: Vladimir Sadovnikov <sadko4u@xxxxxxxxx>
> Signed-off-by: Geoffrey D. Bennett <g@xxxxx>
Tested-by: Markus Schroetter <project.m.schroetter@xxxxxxxxx>
> ---
> sound/usb/mixer_scarlett_gen2.c | 57 +++++++++++++++++++++++++++++++--
> 1 file changed, 55 insertions(+), 2 deletions(-)
>
> diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c
> index 4caf379d5b99..b0043906c77f 100644
> --- a/sound/usb/mixer_scarlett_gen2.c
> +++ b/sound/usb/mixer_scarlett_gen2.c
> @@ -117,11 +117,12 @@
> #define SCARLETT2_MIXER_MAX_DB 6
> #define SCARLETT2_MIXER_MAX_VALUE \
> ((SCARLETT2_MIXER_MAX_DB - SCARLETT2_MIXER_MIN_DB) * 2)
> +#define SCARLETT2_MIXER_VALUE_COUNT (SCARLETT2_MIXER_MAX_VALUE + 1)
>
> /* map from (dB + 80) * 2 to mixer value
> * for dB in 0 .. 172: int(8192 * pow(10, ((dB - 160) / 2 / 20)))
> */
> -static const u16 scarlett2_mixer_values[173] = {
> +static const u16 scarlett2_mixer_values[SCARLETT2_MIXER_VALUE_COUNT] = {
> 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
> 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 8, 8,
> 9, 9, 10, 10, 11, 12, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
> @@ -465,6 +466,7 @@ static int scarlett2_get_port_start_num(const struct scarlett2_ports *ports,
>
> #define SCARLETT2_USB_INIT_SEQ 0x00000000
> #define SCARLETT2_USB_GET_METER_LEVELS 0x00001001
> +#define SCARLETT2_USB_GET_MIX 0x00002001
> #define SCARLETT2_USB_SET_MIX 0x00002002
> #define SCARLETT2_USB_SET_MUX 0x00003002
> #define SCARLETT2_USB_GET_DATA 0x00800000
> @@ -784,6 +786,49 @@ static int scarlett2_usb_get_volume_status(
> buf, sizeof(*buf));
> }
>
> +/* Send a USB message to get the volumes for all inputs of one mix
> + * and put the values into private->mix[]
> + */
> +static int scarlett2_usb_get_mix(struct usb_mixer_interface *mixer,
> + int mix_num)
> +{
> + struct scarlett2_mixer_data *private = mixer->private_data;
> + const struct scarlett2_device_info *info = private->info;
> +
> + int num_mixer_in =
> + info->ports[SCARLETT2_PORT_TYPE_MIX].num[SCARLETT2_PORT_OUT];
> + int err, i, j, k;
> +
> + struct {
> + __le16 mix_num;
> + __le16 count;
> + } __packed req;
> +
> + __le16 data[SCARLETT2_INPUT_MIX_MAX];
> +
> + req.mix_num = mix_num;
> + req.count = num_mixer_in;
> +
> + err = scarlett2_usb(mixer, SCARLETT2_USB_GET_MIX,
> + &req, sizeof(req),
> + data, num_mixer_in * sizeof(u16));
> + if (err < 0)
> + return err;
> +
> + for (i = 0, j = mix_num * num_mixer_in; i < num_mixer_in; i++, j++) {
> + u16 mixer_value = le16_to_cpu(data[i]);
> +
> + for (k = 0; k < SCARLETT2_MIXER_VALUE_COUNT; k++)
> + if (scarlett2_mixer_values[k] >= mixer_value)
> + break;
> + if (k == SCARLETT2_MIXER_VALUE_COUNT)
> + k = SCARLETT2_MIXER_MAX_VALUE;
> + private->mix[j] = k;
> + }
> +
> + return 0;
> +}
> +
> /* Send a USB message to set the volumes for all inputs of one mix
> * (values obtained from private->mix[])
> */
> @@ -1831,7 +1876,7 @@ static int scarlett2_init_private(struct usb_mixer_interface *mixer,
> return scarlett2_usb(mixer, SCARLETT2_USB_INIT_SEQ, NULL, 0, NULL, 0);
> }
>
> -/* Read line-in config and line-out volume settings on start */
> +/* Read configuration from the interface on start */
> static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
> {
> struct scarlett2_mixer_data *private = mixer->private_data;
> @@ -1839,6 +1884,8 @@ static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
> const struct scarlett2_ports *ports = info->ports;
> int num_line_out =
> ports[SCARLETT2_PORT_TYPE_ANALOGUE].num[SCARLETT2_PORT_OUT];
> + int num_mixer_out =
> + ports[SCARLETT2_PORT_TYPE_MIX].num[SCARLETT2_PORT_IN];
> u8 level_switches[SCARLETT2_LEVEL_SWITCH_MAX];
> u8 pad_switches[SCARLETT2_PAD_SWITCH_MAX];
> struct scarlett2_usb_volume_status volume_status;
> @@ -1894,6 +1941,12 @@ static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
> for (i = 0; i < info->button_count; i++)
> private->buttons[i] = !!volume_status.buttons[i];
>
> + for (i = 0; i < num_mixer_out; i++) {
> + err = scarlett2_usb_get_mix(mixer, i);
> + if (err < 0)
> + return err;
> + }
> +
> return 0;
> }
>
