From: Takashi Iwai Date: Wed, 13 Nov 2024 11:10:36 +0000 (+0100) Subject: ALSA: us122l: Use snd_card_free_when_closed() at disconnection X-Git-Tag: v6.11.11~466 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b27924dc8d7f8a8c35e521287d4ccb9a006e597;p=thirdparty%2Fkernel%2Fstable.git 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: 030a07e44129 ("ALSA: Add USB US122L driver") Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20241113111042.15058-3-tiwai@suse.de Signed-off-by: Sasha Levin --- diff --git a/sound/usb/usx2y/us122l.c b/sound/usb/usx2y/us122l.c index 709ccad972e2f..612047ca5fe7a 100644 --- a/sound/usb/usx2y/us122l.c +++ b/sound/usb/usx2y/us122l.c @@ -617,10 +617,7 @@ static void snd_us122l_disconnect(struct usb_interface *intf) usb_put_intf(usb_ifnum_to_if(us122l->dev, 1)); usb_put_dev(us122l->dev); - while (atomic_read(&us122l->mmap_count)) - msleep(500); - - snd_card_free(card); + snd_card_free_when_closed(card); } static int snd_us122l_suspend(struct usb_interface *intf, pm_message_t message)