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| author | Takashi Iwai <tiwai@suse.de> | 2021-09-29 11:08:36 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-09-30 14:55:18 +0300 |
| commit | 4e7cf1fbb34ecb472c073980458cbe413afd4d64 (patch) | |
| tree | 058c5de079f8c9a3e2e1619c6550740d4b59508c /sound/usb/endpoint.c | |
| parent | c4ca3871e21fa085096316f5f8d9975cf3dfde1d (diff) | |
| download | linux-4e7cf1fbb34ecb472c073980458cbe413afd4d64.tar.xz | |
ALSA: usb-audio: Restrict rates for the shared clocks
When a single clock source is shared among several endpoints, we have
to keep the same rate on all active endpoints as long as the clock is
being used. For dealing with such a case, this patch adds one more
check in the hw params constraint for the rate to take the shared
clocks into account. The current rate is evaluated from the endpoint
list that applies the same clock source.
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1190418
Link: https://lore.kernel.org/r/20210929080844.11583-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/endpoint.c')
| -rw-r--r-- | sound/usb/endpoint.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index 533919a28856..29c4865966f5 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -722,6 +722,7 @@ snd_usb_endpoint_open(struct snd_usb_audio *chip, ep->cur_period_frames = params_period_size(params); ep->cur_period_bytes = ep->cur_period_frames * ep->cur_frame_bytes; ep->cur_buffer_periods = params_periods(params); + ep->cur_clock = fp->clock; if (ep->type == SND_USB_ENDPOINT_TYPE_SYNC) endpoint_set_syncinterval(chip, ep); @@ -833,6 +834,7 @@ void snd_usb_endpoint_close(struct snd_usb_audio *chip, ep->altsetting = 0; ep->cur_audiofmt = NULL; ep->cur_rate = 0; + ep->cur_clock = 0; ep->iface_ref = NULL; usb_audio_dbg(chip, "EP 0x%x closed\n", ep->ep_num); } @@ -1340,6 +1342,25 @@ unlock: return err; } +/* get the current rate set to the given clock by any endpoint */ +int snd_usb_endpoint_get_clock_rate(struct snd_usb_audio *chip, int clock) +{ + struct snd_usb_endpoint *ep; + int rate = 0; + + if (!clock) + return 0; + mutex_lock(&chip->mutex); + list_for_each_entry(ep, &chip->ep_list, list) { + if (ep->cur_clock == clock && ep->cur_rate) { + rate = ep->cur_rate; + break; + } + } + mutex_unlock(&chip->mutex); + return rate; +} + /** * snd_usb_endpoint_start: start an snd_usb_endpoint * |