[alsa-devel] [PATCH] ALSA: usb-audio: Fix parameter block size for UAC2 control requests
Takashi Iwai
tiwai at suse.de
Fri Aug 14 15:17:57 CEST 2015
On Thu, 13 Aug 2015 13:04:46 +0200,
Julian Scheel wrote:
>
> USB Audio Class version 2.0 supports three different parameter block sizes for
> CUR requests, which are 1 byte (5.2.3.1 Layout 1 Parameter Block), 2 bytes
> (5.2.3.2 Layout 2 Parameter Block) and 4 bytes (5.2.3.3 Layout 3 Parameter
> Block). Use the correct size according to the specific control as it was
> already done for UACv1. The allocated block size for control requests is
> increased to support the 4 byte worst case.
>
> Signed-off-by: Julian Scheel <julian at jusst.de>
> ---
> sound/usb/mixer.c | 83 +++++++++++++++++++++++++++++++++++++++++--------------
> sound/usb/mixer.h | 2 ++
> 2 files changed, 65 insertions(+), 20 deletions(-)
>
> diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
> index 4a49944..675725b 100644
> --- a/sound/usb/mixer.c
> +++ b/sound/usb/mixer.c
> @@ -233,6 +233,14 @@ static int convert_signed_value(struct usb_mixer_elem_info *cval, int val)
> if (val >= 0x8000)
> val -= 0x10000;
> break;
> + case USB_MIXER_U32:
> + val &= 0xffffffff;
> + break;
> + case USB_MIXER_S32:
> + val &= 0xffffffff;
> + if (val >= 0x80000000)
> + val -= 0x100000000;
> + break;
All these are superfluous, as int on Linux is always 32bit.
> }
> return val;
> }
> @@ -253,6 +261,9 @@ static int convert_bytes_value(struct usb_mixer_elem_info *cval, int val)
> case USB_MIXER_S16:
> case USB_MIXER_U16:
> return val & 0xffff;
> + case USB_MIXER_S32:
> + case USB_MIXER_U32:
> + return val & 0xffffffff;
Ditto.
> }
> return 0; /* not reached */
> }
> @@ -328,14 +339,26 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request,
> int validx, int *value_ret)
> {
> struct snd_usb_audio *chip = cval->head.mixer->chip;
> - unsigned char buf[2 + 3 * sizeof(__u16)]; /* enough space for one range */
> + unsigned char buf[4 + 3 * sizeof(__u32)]; /* enough space for one range */
> unsigned char *val;
> int idx = 0, ret, size;
> __u8 bRequest;
>
> if (request == UAC_GET_CUR) {
> bRequest = UAC2_CS_CUR;
> - size = sizeof(__u16);
> + switch (cval->val_type) {
> + case USB_MIXER_S32:
> + case USB_MIXER_U32:
> + size = 4;
> + break;
> + case USB_MIXER_S16:
> + case USB_MIXER_U16:
> + size = 2;
> + break;
> + default:
> + size = 1;
> + break;
Please split this into a small helper function,
e.g. uac2_ctl_value_size(). The same stuff is used in below, too.
> + }
> } else {
> bRequest = UAC2_CS_RANGE;
> size = sizeof(buf);
> @@ -446,7 +469,7 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
> int request, int validx, int value_set)
> {
> struct snd_usb_audio *chip = cval->head.mixer->chip;
> - unsigned char buf[2];
> + unsigned char buf[4];
> int idx = 0, val_len, err, timeout = 10;
>
> validx += cval->idx_off;
> @@ -454,8 +477,19 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
> if (cval->head.mixer->protocol == UAC_VERSION_1) {
> val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
> } else { /* UAC_VERSION_2 */
> - /* audio class v2 controls are always 2 bytes in size */
> - val_len = sizeof(__u16);
> + switch (cval->val_type) {
> + case USB_MIXER_S32:
> + case USB_MIXER_U32:
> + val_len = 4;
> + break;
> + case USB_MIXER_S16:
> + case USB_MIXER_U16:
> + val_len = 2;
> + break;
> + default:
> + val_len = 1;
> + break;
> + }
>
> /* FIXME */
> if (request != UAC_SET_CUR) {
> @@ -469,6 +503,8 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
> value_set = convert_bytes_value(cval, value_set);
> buf[0] = value_set & 0xff;
> buf[1] = (value_set >> 8) & 0xff;
> + buf[2] = (value_set >> 16) & 0xff;
> + buf[3] = (value_set >> 24) & 0xff;
It's not smart but OK, just a subtle matter...
> err = snd_usb_autoresume(chip);
> if (err < 0)
> return -EIO;
> @@ -799,24 +835,25 @@ static int check_input_term(struct mixer_build *state, int id,
> /* feature unit control information */
> struct usb_feature_control_info {
> const char *name;
> - unsigned int type; /* control type (mute, volume, etc.) */
> + int type; /* data type for uac1 */
> + int type_uac2; /* data type for uac2 if different from uac1, else -1 */
> };
>
> static struct usb_feature_control_info audio_feature_info[] = {
> - { "Mute", USB_MIXER_INV_BOOLEAN },
> - { "Volume", USB_MIXER_S16 },
> - { "Tone Control - Bass", USB_MIXER_S8 },
> - { "Tone Control - Mid", USB_MIXER_S8 },
> - { "Tone Control - Treble", USB_MIXER_S8 },
> - { "Graphic Equalizer", USB_MIXER_S8 }, /* FIXME: not implemeted yet */
> - { "Auto Gain Control", USB_MIXER_BOOLEAN },
> - { "Delay Control", USB_MIXER_U16 }, /* FIXME: U32 in UAC2 */
> - { "Bass Boost", USB_MIXER_BOOLEAN },
> - { "Loudness", USB_MIXER_BOOLEAN },
> + { "Mute", USB_MIXER_INV_BOOLEAN, -1 },
> + { "Volume", USB_MIXER_S16, -1 },
> + { "Tone Control - Bass", USB_MIXER_S8, -1 },
> + { "Tone Control - Mid", USB_MIXER_S8, -1 },
> + { "Tone Control - Treble", USB_MIXER_S8, -1 },
> + { "Graphic Equalizer", USB_MIXER_S8, -1 }, /* FIXME: not implemeted yet */
> + { "Auto Gain Control", USB_MIXER_BOOLEAN, -1 },
> + { "Delay Control", USB_MIXER_U16, USB_MIXER_U32 },
> + { "Bass Boost", USB_MIXER_BOOLEAN, -1 },
> + { "Loudness", USB_MIXER_BOOLEAN, -1 },
> /* UAC2 specific */
> - { "Input Gain Control", USB_MIXER_S16 },
> - { "Input Gain Pad Control", USB_MIXER_S16 },
> - { "Phase Inverter Control", USB_MIXER_BOOLEAN },
> + { "Input Gain Control", USB_MIXER_S16, -1 },
> + { "Input Gain Pad Control", USB_MIXER_S16, -1 },
> + { "Phase Inverter Control", USB_MIXER_BOOLEAN, -1 },
> };
>
> /* private_free callback */
> @@ -1241,7 +1278,13 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc,
> snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
> cval->control = control;
> cval->cmask = ctl_mask;
> - cval->val_type = audio_feature_info[control-1].type;
> + if (state->mixer->protocol == UAC_VERSION_1)
> + cval->val_type = audio_feature_info[control-1].type;
> + else /* UAC_VERSION_2 */
> + cval->val_type = audio_feature_info[control-1].type_uac2 > -1 ?
Usually ">= 0" is used.
> + audio_feature_info[control-1].type_uac2 :
> + audio_feature_info[control-1].type;
Since audio_feature_info[control-1] is referred so many times, it's
better to put in a temporary variable.
thanks,
Takashi
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