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authorTakashi Iwai <tiwai@suse.de>2022-10-09 12:42:09 +0200
committerTakashi Iwai <tiwai@suse.de>2022-10-09 12:43:24 +0200
commit9902b303b5ade208b58f0dd38a09831813582211 (patch)
treeb74c15b89dc278f2d747c186ed21dee62ad910d2 /sound/usb
parentALSA: hda: Update register polling macros (diff)
downloadlinux-dev-9902b303b5ade208b58f0dd38a09831813582211.tar.xz
linux-dev-9902b303b5ade208b58f0dd38a09831813582211.zip
ALSA: usb-audio: Avoid unnecessary interface change at EP close
We toggle USB interface at PCM prepare and reset at close. When the PCM isn't prepared, resetting again makes little sense. Check the current altset and avoid unnecessary interface reset at EP close. Link: https://lore.kernel.org/r/20221009104212.18877-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb')
-rw-r--r--sound/usb/endpoint.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 48a3843a08f1..f21acbc9f4f4 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -32,6 +32,7 @@ struct snd_usb_iface_ref {
unsigned char iface;
bool need_setup;
int opened;
+ int altset;
struct list_head list;
};
@@ -899,6 +900,9 @@ static int endpoint_set_interface(struct snd_usb_audio *chip,
int altset = set ? ep->altsetting : 0;
int err;
+ if (ep->iface_ref->altset == altset)
+ return 0;
+
usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",
ep->iface, altset, ep->ep_num);
err = usb_set_interface(chip->dev, ep->iface, altset);
@@ -910,6 +914,7 @@ static int endpoint_set_interface(struct snd_usb_audio *chip,
if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
msleep(50);
+ ep->iface_ref->altset = altset;
return 0;
}