| Message ID | 1439463886-5369-1-git-send-email-julian@jusst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@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
Am 14.08.2015 um 15:17 schrieb Takashi Iwai: > 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@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. Of course. Thanks. >> } >> 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. Ack. >> + } >> } 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... Hm, what would you like better? >> 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. Ack. >> + 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. Ack. Thanks for reviewing! -Julian
On Fri, 14 Aug 2015 15:45:58 +0200, Julian Scheel wrote: > > Am 14.08.2015 um 15:17 schrieb Takashi Iwai: > > On Thu, 13 Aug 2015 13:04:46 +0200, > > Julian Scheel wrote: > >> > >> @@ -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... > > Hm, what would you like better? A shorter code would be to to pass __le32 value pointer directly after calling cpu_to_le32(), for example. But it's a matter of taste, so it's OK to keep your code as is. Takashi
Am 14.08.2015 um 15:51 schrieb Takashi Iwai: > On Fri, 14 Aug 2015 15:45:58 +0200, > Julian Scheel wrote: >> >> Am 14.08.2015 um 15:17 schrieb Takashi Iwai: >>> On Thu, 13 Aug 2015 13:04:46 +0200, >>> Julian Scheel wrote: >>>> >>>> @@ -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... >> >> Hm, what would you like better? > > A shorter code would be to to pass __le32 value pointer directly after > calling cpu_to_le32(), for example. But it's a matter of taste, so > it's OK to keep your code as is. Thanks, I'll leave it as is for now and keep the le32 approach in mind for the future.
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; } 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; } 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; + } } 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; 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 ? + audio_feature_info[control-1].type_uac2 : + audio_feature_info[control-1].type; + if (ctl_mask == 0) { cval->channels = 1; /* master channel */ cval->master_readonly = readonly_mask; diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h index d3268f0..3417ef3 100644 --- a/sound/usb/mixer.h +++ b/sound/usb/mixer.h @@ -33,6 +33,8 @@ enum { USB_MIXER_U8, USB_MIXER_S16, USB_MIXER_U16, + USB_MIXER_S32, + USB_MIXER_U32, }; typedef void (*usb_mixer_elem_dump_func_t)(struct snd_info_buffer *buffer,
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@jusst.de> --- sound/usb/mixer.c | 83 +++++++++++++++++++++++++++++++++++++++++-------------- sound/usb/mixer.h | 2 ++ 2 files changed, 65 insertions(+), 20 deletions(-)