| Message ID | 1460137922-8993-1-git-send-email-daniel@zonque.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 08 Apr 2016 19:52:01 +0200, Daniel Mack wrote: > > UAC2 specifies clock sources that optionally have validity controls. > This patch exposes them as mixer controls, so they can be read (and > at least in theory even be written) by userspace applications in order > to make clock selection policy decisions. > > This implementation does nothing if the device is not UAC2 compliant, > or if the clock source does not define said validity control bits. > > Tested with a miniDSP USBStreamer (0x2752/0x0016), > > Signed-off-by: Daniel Mack <daniel@zonque.org> > --- > sound/usb/mixer.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 65 insertions(+), 1 deletion(-) > > diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c > index 4f85757..973274b 100644 > --- a/sound/usb/mixer.c > +++ b/sound/usb/mixer.c > @@ -45,6 +45,7 @@ > #include <linux/bitops.h> > #include <linux/init.h> > #include <linux/list.h> > +#include <linux/log2.h> > #include <linux/slab.h> > #include <linux/string.h> > #include <linux/usb.h> > @@ -1378,6 +1379,68 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc, > snd_usb_mixer_add_control(&cval->head, kctl); > } > > +static int parse_clock_source_unit(struct mixer_build *state, int unitid, > + void *_ftr) > + > +{ > + struct uac_clock_source_descriptor *hdr = _ftr; > + struct usb_mixer_elem_info *cval; > + struct snd_kcontrol *kctl; > + char name[100]; No need for 100. SNDRV_CTL_ELEM_ID_NAME_MAXLEN should suffice. > + int ret; > + > + if (state->mixer->protocol != UAC_VERSION_2) > + return -EINVAL; > + > + if (hdr->bLength != sizeof(*hdr)) > + return -EINVAL; I wonder whether we should abort here and return an error. It's a wacky firmware, and no kernel error, after all. > + /* > + * The only property of this unit we are interested in is the > + * clock source validity. If that isn't readable, just bail out. > + */ > + if (!uac2_control_is_readable(hdr->bmControls, > + ilog2(UAC2_CS_CONTROL_CLOCK_VALID))) > + return 0; > + > + cval = kzalloc(sizeof(*cval), GFP_KERNEL); > + if (!cval) > + return -ENOMEM; > + > + snd_usb_mixer_elem_init_std(&cval->head, state->mixer, hdr->bClockID); > + > + cval->min = 0; > + cval->max = 1; > + cval->channels = 1; > + cval->val_type = USB_MIXER_BOOLEAN; > + cval->control = UAC2_CS_CONTROL_CLOCK_VALID; > + > + if (uac2_control_is_writeable(hdr->bmControls, > + ilog2(UAC2_CS_CONTROL_CLOCK_VALID))) > + kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval); > + else { > + cval->master_readonly = 1; > + kctl = snd_ctl_new1(&usb_feature_unit_ctl_ro, cval); > + } > + > + if (!kctl) { > + kfree(cval); > + return -ENOMEM; > + } > + > + kctl->private_free = snd_usb_mixer_elem_free; > + ret = snd_usb_copy_string_desc(state, hdr->iClockSource, > + name, sizeof(name)); > + if (ret > 0) > + snprintf(kctl->id.name, sizeof(kctl->id.name), > + "%s validity", name); > + else > + snprintf(kctl->id.name, sizeof(kctl->id.name), > + "Clock source %d validity", hdr->bClockID); Each word in control name is usually starting with a capital letter. thanks, Takashi
Hi Takashi, On 04/09/2016 10:43 AM, Takashi Iwai wrote: > On Fri, 08 Apr 2016 19:52:01 +0200, > Daniel Mack wrote: >> >> UAC2 specifies clock sources that optionally have validity controls. >> This patch exposes them as mixer controls, so they can be read (and >> at least in theory even be written) by userspace applications in order >> to make clock selection policy decisions. >> >> This implementation does nothing if the device is not UAC2 compliant, >> or if the clock source does not define said validity control bits. >> >> Tested with a miniDSP USBStreamer (0x2752/0x0016), >> >> Signed-off-by: Daniel Mack <daniel@zonque.org> >> --- >> sound/usb/mixer.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- >> 1 file changed, 65 insertions(+), 1 deletion(-) >> >> diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c >> index 4f85757..973274b 100644 >> --- a/sound/usb/mixer.c >> +++ b/sound/usb/mixer.c >> @@ -45,6 +45,7 @@ >> #include <linux/bitops.h> >> #include <linux/init.h> >> #include <linux/list.h> >> +#include <linux/log2.h> >> #include <linux/slab.h> >> #include <linux/string.h> >> #include <linux/usb.h> >> @@ -1378,6 +1379,68 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc, >> snd_usb_mixer_add_control(&cval->head, kctl); >> } >> >> +static int parse_clock_source_unit(struct mixer_build *state, int unitid, >> + void *_ftr) >> + >> +{ >> + struct uac_clock_source_descriptor *hdr = _ftr; >> + struct usb_mixer_elem_info *cval; >> + struct snd_kcontrol *kctl; >> + char name[100]; > > No need for 100. SNDRV_CTL_ELEM_ID_NAME_MAXLEN should suffice. > >> + int ret; >> + >> + if (state->mixer->protocol != UAC_VERSION_2) >> + return -EINVAL; >> + >> + if (hdr->bLength != sizeof(*hdr)) >> + return -EINVAL; > > I wonder whether we should abort here and return an error. > It's a wacky firmware, and no kernel error, after all. This is what we're doing in other parsers as well, but you're right, it's better to just add a debug print here and handle this gracefully. Will send a new patch soon, also addressing the other details. Thanks, Daniel
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 4f85757..973274b 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -45,6 +45,7 @@ #include <linux/bitops.h> #include <linux/init.h> #include <linux/list.h> +#include <linux/log2.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/usb.h> @@ -1378,6 +1379,68 @@ static void build_feature_ctl(struct mixer_build *state, void *raw_desc, snd_usb_mixer_add_control(&cval->head, kctl); } +static int parse_clock_source_unit(struct mixer_build *state, int unitid, + void *_ftr) + +{ + struct uac_clock_source_descriptor *hdr = _ftr; + struct usb_mixer_elem_info *cval; + struct snd_kcontrol *kctl; + char name[100]; + int ret; + + if (state->mixer->protocol != UAC_VERSION_2) + return -EINVAL; + + if (hdr->bLength != sizeof(*hdr)) + return -EINVAL; + + /* + * The only property of this unit we are interested in is the + * clock source validity. If that isn't readable, just bail out. + */ + if (!uac2_control_is_readable(hdr->bmControls, + ilog2(UAC2_CS_CONTROL_CLOCK_VALID))) + return 0; + + cval = kzalloc(sizeof(*cval), GFP_KERNEL); + if (!cval) + return -ENOMEM; + + snd_usb_mixer_elem_init_std(&cval->head, state->mixer, hdr->bClockID); + + cval->min = 0; + cval->max = 1; + cval->channels = 1; + cval->val_type = USB_MIXER_BOOLEAN; + cval->control = UAC2_CS_CONTROL_CLOCK_VALID; + + if (uac2_control_is_writeable(hdr->bmControls, + ilog2(UAC2_CS_CONTROL_CLOCK_VALID))) + kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval); + else { + cval->master_readonly = 1; + kctl = snd_ctl_new1(&usb_feature_unit_ctl_ro, cval); + } + + if (!kctl) { + kfree(cval); + return -ENOMEM; + } + + kctl->private_free = snd_usb_mixer_elem_free; + ret = snd_usb_copy_string_desc(state, hdr->iClockSource, + name, sizeof(name)); + if (ret > 0) + snprintf(kctl->id.name, sizeof(kctl->id.name), + "%s validity", name); + else + snprintf(kctl->id.name, sizeof(kctl->id.name), + "Clock source %d validity", hdr->bClockID); + + return snd_usb_mixer_add_control(&cval->head, kctl); +} + /* * parse a feature unit * @@ -2126,10 +2189,11 @@ static int parse_audio_unit(struct mixer_build *state, int unitid) switch (p1[2]) { case UAC_INPUT_TERMINAL: - case UAC2_CLOCK_SOURCE: return 0; /* NOP */ case UAC_MIXER_UNIT: return parse_audio_mixer_unit(state, unitid, p1); + case UAC2_CLOCK_SOURCE: + return parse_clock_source_unit(state, unitid, p1); case UAC_SELECTOR_UNIT: case UAC2_CLOCK_SELECTOR: return parse_audio_selector_unit(state, unitid, p1);
UAC2 specifies clock sources that optionally have validity controls. This patch exposes them as mixer controls, so they can be read (and at least in theory even be written) by userspace applications in order to make clock selection policy decisions. This implementation does nothing if the device is not UAC2 compliant, or if the clock source does not define said validity control bits. Tested with a miniDSP USBStreamer (0x2752/0x0016), Signed-off-by: Daniel Mack <daniel@zonque.org> --- sound/usb/mixer.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 65 insertions(+), 1 deletion(-)