ALSA: us122l: Use snd_card_free_when_closed() at disconnection

[ Upstream commit b7df09bb348016943f56b09dcaafe221e3f73947 ]

The USB disconnect callback is supposed to be short and not too-long
waiting.  OTOH, the current code uses snd_card_free() at
disconnection, but this waits for the close of all used fds, hence it
can take long.  It eventually blocks the upper layer USB ioctls, which
may trigger a soft lockup.

An easy workaround is to replace snd_card_free() with
snd_card_free_when_closed().  This variant returns immediately while
the release of resources is done asynchronously by the card device
release at the last close.

The loop of us122l->mmap_count check is dropped as well.  The check is
useless for the asynchronous operation with *_when_closed().

Fixes: 030a07e441 ("ALSA: Add USB US122L driver")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20241113111042.15058-3-tiwai@suse.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Takashi Iwai 2024-11-13 12:10:36 +01:00 committed by Greg Kroah-Hartman
parent 71d55e19fe
commit 75f418b249

View file

@ -636,10 +636,7 @@ static void snd_us122l_disconnect(struct usb_interface *intf)
usb_put_intf(usb_ifnum_to_if(us122l->dev, 1)); usb_put_intf(usb_ifnum_to_if(us122l->dev, 1));
usb_put_dev(us122l->dev); usb_put_dev(us122l->dev);
while (atomic_read(&us122l->mmap_count)) snd_card_free_when_closed(card);
msleep(500);
snd_card_free(card);
} }
static int snd_us122l_suspend(struct usb_interface *intf, pm_message_t message) static int snd_us122l_suspend(struct usb_interface *intf, pm_message_t message)