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authorEldad Zack <eldad@fogrefinery.com>2013-04-03 23:18:55 +0200
committerTakashi Iwai <tiwai@suse.de>2013-04-04 08:31:14 +0200
commit8c55af3f69be6021631628b968cad301d3f294c8 (patch)
tree049cd4e6cc4aa6c5fb7143d719fecee2f6c93025 /sound/usb/clock.c
parentALSA: usb-audio: UAC2: do clock validity check earlier (diff)
downloadlinux-8c55af3f69be6021631628b968cad301d3f294c8.tar.xz
linux-8c55af3f69be6021631628b968cad301d3f294c8.zip
ALSA: usb-audio: UAC2: try to find and switch to valid clock
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> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/clock.c')
-rw-r--r--sound/usb/clock.c69
1 files changed, 66 insertions, 3 deletions
diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index 0c98f52a1c9c..d7ab2d75aefd 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;