On Thu, 04 Feb 2021 20:39:06 +0100,
Olivia Mackintosh wrote:
>
> This allows for N different devices to use the pioneer mixer quirk for
> setting capture/record type and recording level. The impementation has
> not changed much with the exception of an additional mask on
> private_value to allow storing of a device index:
> DEVICE MASK 0xff000000
> GROUP_MASK 0x00ff0000
> VALUE_MASK 0x0000ffff
>
> There is perhaps room for removing the duplication in the lookup tables
> (name, wValue, wIndex) and deriving these. See the code header comment
> to understand how this can be achieved.
>
> Feedback is very much appreciated as I'm not the most proficient C
> programmer but am learning as I go.
>
> Signed-off-by: Olivia Mackintosh <livvy@xxxxxxx>
The patch looks almost good, below are just some nitpicking.
> --- a/sound/usb/mixer_quirks.c
> +++ b/sound/usb/mixer_quirks.c
> @@ -2602,142 +2602,218 @@ static int snd_bbfpro_controls_create(struct usb_mixer_interface *mixer)
> return 0;
> }
>
> +
No need to add more empty line here.
> +struct snd_djm_device {
> + char *name;
> + const struct snd_djm_ctl *controls;
> + const size_t ncontrols;
The const to ncontrols is almost useless.
> +struct snd_djm_ctl {
> + const char *name;
> + const u16 *options;
> + const size_t noptions;
> + const u16 default_value;
> + const u16 wIndex;
Ditto, const for integers are superfluous.
> +static char *snd_djm_get_label_caplevel(u16 wvalue)
This should have const instead.
> +{
> + switch (wvalue) {
> + case 0x0000: return "-19dB";
> + case 0x0100: return "-15dB";
> + case 0x0200: return "-10dB";
> + case 0x0300: return "-5dB";
> + default: return "\0"; // 'EINVAL'
Let return NULL for the error instead.
> +static char *snd_djm_get_label_cap(u16 wvalue)
Use const.
> +{
> + switch (wvalue & 0x00ff) {
> + case SND_DJM_CAP_LINE: return "Control Tone LINE\0";
The trainling '\0' is superfluous. Ditto in other lines.
> + default: return "\0"; // 'EINVAL'
Let's use NULL.
> +static char *snd_djm_get_label_pb(u16 wvalue)
Use const.
> +{
> + switch (wvalue & 0x00ff) {
> + case SND_DJM_PB_CH1: return "Ch1\0";
> + case SND_DJM_PB_CH2: return "Ch2\0";
> + case SND_DJM_PB_AUX: return "Aux\0";
> + default: return "\0"; // 'EINVAL'
Like the above.
> +static char *snd_djm_get_label(u16 wvalue, u16 windex)
Use const.
> +{
> + switch (windex) {
> + case SND_DJM_WINDEX_CAPLVL: return snd_djm_get_label_caplevel(wvalue);
> + case SND_DJM_WINDEX_CAP: return snd_djm_get_label_cap(wvalue);
> + case SND_DJM_WINDEX_PB: return snd_djm_get_label_pb(wvalue);
> + default: return "\0"; // 'EINVAL';
Use NULL.
> -static int snd_pioneer_djm_controls_info(struct snd_kcontrol *kctl, struct snd_ctl_elem_info *info)
> +static int snd_djm_controls_info(struct snd_kcontrol *kctl,
> + struct snd_ctl_elem_info *info)
> {
> - u16 group_index = kctl->private_value >> SND_PIONEER_DJM_GROUP_SHIFT;
> - size_t count;
> + unsigned long private_value = kctl->private_value;
> + u8 device_idx = (private_value & SND_DJM_DEVICE_MASK) >> SND_DJM_DEVICE_SHIFT;
> + u8 ctl_idx = (private_value & SND_DJM_GROUP_MASK) >> SND_DJM_GROUP_SHIFT;
> + const struct snd_djm_device device = snd_djm_devices[device_idx];
This will end up copying the whole struct on a stack.
Instead,
const struct snd_djm_device *device = &snd_djm_devices[device_idx];
and access via
device->ncontrols
> + name = snd_djm_get_label(
> + ctl->options[info->value.enumerated.item],
> + ctl->wIndex
> + );
It's better not to put a line-break after the open parenthesis.
name = snd_djm_get_label(ctl->options[info->value.enumerated.item],
ctl->wIndex);
> + if (strlen(name) == 0)
> return -EINVAL;
If the functions above return NULL for errors, this can be simplified
as:
if (!name)
return -EINVAL;
> -static int snd_pioneer_djm_controls_update(struct usb_mixer_interface *mixer, u16 group, u16 value)
> +static int snd_djm_controls_update(struct usb_mixer_interface *mixer,
> + u8 device_idx, u8 group, u16 value)
> {
> int err;
> + const struct snd_djm_device *device = &snd_djm_devices[device_idx];
Funnily, here you're doing right :)
> +static int snd_djm_controls_create(struct usb_mixer_interface *mixer,
> + const u8 device_idx)
> {
> int err, i;
> - const struct snd_pioneer_djm_option_group *group;
> + u16 value;
> +
> + const struct snd_djm_device device = snd_djm_devices[device_idx];
... but here not.
thanks,
Takashi
