If a selector is available on a device, it may be pointing to a clock source which is currently invalid. If there is a valid clock source which can be selected, switch to it.
Signed-off-by: Eldad Zack eldad@fogrefinery.com --- sound/usb/clock.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 66 insertions(+), 3 deletions(-)
diff --git a/sound/usb/clock.c b/sound/usb/clock.c index 0c98f52..d7ab2d7 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -99,6 +99,41 @@ static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_i return buf; }
+static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id, + unsigned char pin) +{ + int ret; + + ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), + UAC2_CS_CUR, + USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT, + UAC2_CX_CLOCK_SELECTOR << 8, + snd_usb_ctrl_intf(chip) | (selector_id << 8), + &pin, sizeof(pin)); + if (ret < 0) + return ret; + + if (ret != sizeof(pin)) { + snd_printk(KERN_ERR + "usb-audio:%d: setting selector (id %d) unexpected length %d\n", + chip->dev->devnum, selector_id, ret); + return -EINVAL; + } + + ret = uac_clock_selector_get_val(chip, selector_id); + if (ret < 0) + return ret; + + if (ret != pin) { + snd_printk(KERN_ERR + "usb-audio:%d: setting selector (id %d) to %x failed (current: %d)\n", + chip->dev->devnum, selector_id, pin, ret); + return -EINVAL; + } + + return ret; +} + static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id) { int err; @@ -161,7 +196,7 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip,
selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id); if (selector) { - int ret; + int ret, i, cur;
/* the entity ID we are looking for is a selector. * find out what it currently selects */ @@ -179,8 +214,35 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip, return -EINVAL; }
- return __uac_clock_find_source(chip, selector->baCSourceID[ret-1], + cur = ret; + ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1], visited, validate); + if (!validate || ret > 0) + return ret; + + /* The current clock source is invalid, try others. */ + for (i = 1; i <= selector->bNrInPins; i++) { + int err; + + if (i == cur) + continue; + + ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1], + visited, true); + if (ret < 0) + continue; + + err = uac_clock_selector_set_val(chip, entity_id, i); + if (err < 0) + continue; + + snd_printk(KERN_INFO + "usb-audio:%d: found and selected valid clock source %d\n", + chip->dev->devnum, ret); + return ret; + } + + return -ENXIO; }
/* FIXME: multipliers only act as pass-thru element for now */ @@ -284,8 +346,9 @@ static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface, struct usb_device *dev = chip->dev; __le32 data; int err, cur_rate, prev_rate; - int clock = snd_usb_clock_find_source(chip, fmt->clock, true); + int clock;
+ clock = snd_usb_clock_find_source(chip, fmt->clock, true); if (clock < 0) return clock;