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| author | Takashi Iwai <tiwai@suse.de> | 2020-11-23 09:53:34 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2020-11-23 15:15:48 +0100 |
| commit | 43b81e84068d26d630b63fa877e682909a0102fe (patch) | |
| tree | ce23f626a7cdc49a67a539c6e2080e10279bce0b /sound/usb/card.h | |
| parent | cab941b7e5cf054502b01f776db724400ee5c1b6 (diff) | |
| download | linux-43b81e84068d26d630b63fa877e682909a0102fe.tar.bz2 | |
ALSA: usb-audio: Use atomic_t for endpoint use_count
The endpoint objects may be started/stopped concurrently by different
substreams in the case of implicit feedback mode, while the current
code handles the reference counter without any protection.
This patch changes the refcount to atomic_t for avoiding the
inconsistency. We need no reference_t here as the refcount goes only
up to 2.
Also the name "use_count" is renamed to "running" since this is about
actually the running status, not the open refcount.
Tested-by: Keith Milner <kamilner@superlative.org>
Tested-by: Dylan Robinson <dylan_robinson@motu.com>
Link: https://lore.kernel.org/r/20201123085347.19667-29-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/card.h')
| -rw-r--r-- | sound/usb/card.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/usb/card.h b/sound/usb/card.h index 53f0ce61f858..f58c3769b058 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -60,7 +60,7 @@ struct snd_usb_endpoint { struct snd_usb_audio *chip; int opened; /* open refcount; protect with chip->mutex */ - int use_count; + atomic_t running; /* running status */ int ep_num; /* the referenced endpoint number */ int type; /* SND_USB_ENDPOINT_TYPE_* */ unsigned long flags; |