[PATCH 1/2] ALSA: usb-audio: Fix packet size calculation

Alexander Tsoy alexander at tsoy.me
Mon Jun 29 04:59:33 CEST 2020


Commit f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation")
introduced a regression for devices which have playback endpoints with
bInterval > 1. Fix this by taking ep->datainterval into account.

Note that frame and fps are actually mean packet and packets per second
in the code introduces by the mentioned commit. This will be fixed in a
follow-up patch.

Fixes: f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation")
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=208353
Signed-off-by: Alexander Tsoy <alexander at tsoy.me>
---
 sound/usb/endpoint.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 9bea7d3f99f8..11f23778f0a5 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -1093,6 +1093,7 @@ int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
 		ep->freqn = get_usb_high_speed_rate(rate);
 		ep->fps = 8000;
 	}
+	ep->fps >>= ep->datainterval;
 
 	ep->sample_rem = rate % ep->fps;
 	ep->framesize[0] = rate / ep->fps;
-- 
2.26.2



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