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

From: Alexander Tsoy <alexander@tsoy.me>
To: alsa-devel@alsa-project.org
Cc: Takashi Iwai <tiwai@suse.de>, Peter Bui <pbui@kernel.bx612.space>
Subject: [PATCH 1/2] ALSA: usb-audio: Fix packet size calculation
Date: Mon, 29 Jun 2020 05:59:33 +0300	[thread overview]
Message-ID: <20200629025934.154288-1-alexander@tsoy.me> (raw)

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@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

