From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Takashi Iwai <tiwai@suse.de>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.12.y 1/2] ALSA: usb-audio: Optimize the copy of packet sizes for implicit fb handling
Date: Tue, 22 Sep 2026 08:34:39 -0400 [thread overview]
Message-ID: <20260922123440.2257183-1-sashal@kernel.org> (raw)
In-Reply-To: <2026092246-smasher-unpleased-5c4c@gregkh>
From: Takashi Iwai <tiwai@suse.de>
[ Upstream commit 36adb51ac0b19edb32ffeea3fe66b174bad25ead ]
We did manual copies over loop for the packet data update of the
implicit feedback, but this can be optimized with a simple memcpy().
Along with it, change the data type of snd_usb_packet_info struct to
align with other (from uint32_t to int).
No functional changes but only code optimizations.
Link: https://patch.msgid.link/20260216141209.1849200-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Stable-dep-of: 76a986c980bb ("ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/usb/card.h | 2 +-
sound/usb/endpoint.c | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 6ec95b2edf863..ac5505ce046de 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -89,7 +89,7 @@ struct snd_usb_endpoint {
struct snd_urb_ctx urb[MAX_URBS];
struct snd_usb_packet_info {
- uint32_t packet_size[MAX_PACKS_HS];
+ int packet_size[MAX_PACKS_HS];
int packets;
} next_packet[MAX_URBS];
unsigned int next_packet_head; /* ring buffer offset to read */
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index c573d74641d42..77e2887e81ae2 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -478,7 +478,7 @@ int snd_usb_queue_pending_output_urbs(struct snd_usb_endpoint *ep,
unsigned long flags;
struct snd_usb_packet_info *packet;
struct snd_urb_ctx *ctx = NULL;
- int err, i;
+ int err;
spin_lock_irqsave(&ep->lock, flags);
if ((!implicit_fb || ep->next_packet_queued > 0) &&
@@ -498,8 +498,8 @@ 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];
+ memcpy(ctx->packet_size, packet->packet_size,
+ packet->packets * sizeof(packet->packet_size[0]));
}
/* call the data handler to fill in playback data */
--
2.53.0
next prev parent reply other threads:[~2026-09-22 12:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-22 8:24 FAILED: patch "[PATCH] ALSA: usb-audio: Clamp implicit feedback packet count to URB" failed to apply to 6.12-stable tree gregkh
2026-09-22 12:34 ` Sasha Levin [this message]
2026-09-22 12:34 ` [PATCH 6.12.y 2/2] ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity Sasha Levin
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