From: Takashi Iwai <tiwai@suse.de>
Date: Mon, 16 Feb 2026 14:12:05 +0000 (+0100)
Subject: ALSA: usb-audio: Update the number of packets properly at receiving
X-Git-Tag: v6.19.6~421
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f6fbdf797e016fbf968dd54301026b182175985a;p=thirdparty%2Fkernel%2Fstable.git

ALSA: usb-audio: Update the number of packets properly at receiving

[ Upstream commit cf044e44190234a41a788de1cdbb6c21f4a52e1e ]

At receiving the packets from the implicit feedback source, we didn't
update ctx->packets field but only the ctx->packet_size[] data.
In exceptional cases, this might lead to unexpectedly superfluous data
transfer (although this won't happen usually due to the nature of USB
isochronous transfer).  Fix it to update the field properly.

Link: https://patch.msgid.link/20260216141209.1849200-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 8f9313857ee9d..27ade2aa16f5a 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -481,6 +481,7 @@ int snd_usb_queue_pending_output_urbs(struct snd_usb_endpoint *ep,
 
 		/* copy over the length information */
 		if (implicit_fb) {
+			ctx->packets = packet->packets;
 			for (i = 0; i < packet->packets; i++)
 				ctx->packet_size[i] = packet->packet_size[i];
 		}