diff options
| author | Takashi Iwai <tiwai@suse.de> | 2014-05-02 18:17:06 +0200 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-08-04 16:51:53 +0200 |
| commit | 8986a67aa7da0e7c6dc8e595f6aa8401b655d02d (patch) | |
| tree | 797b1e087b1fd2c407eecc3f207037ea0b6b6552 /sound | |
| parent | 708183150dad5f6a2bdde67e8292954012782171 (diff) | |
ALSA: usb-audio: Fix deadlocks at resuming
commit 1ee23fe07ee83a38ecee927e701f762888ada942 upstream.
The recent addition of the USB audio mixer suspend/resume may lead to
deadlocks when the driver tries to call usb_autopm_get_interface()
recursively, since the function tries to sync with the finish of the
other calls. For avoiding it, introduce a flag indicating the resume
operation and avoids the recursive usb_autopm_get_interface() calls
during the resume.
Reported-and-tested-by: Bryan Quigley <gquigs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/usb/card.c | 7 | ||||
| -rw-r--r-- | sound/usb/usbaudio.h | 1 |
2 files changed, 6 insertions, 2 deletions
diff --git a/sound/usb/card.c b/sound/usb/card.c index ca55e033cf9d..bc5795f342a7 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -661,7 +661,7 @@ int snd_usb_autoresume(struct snd_usb_audio *chip) int err = -ENODEV; down_read(&chip->shutdown_rwsem); - if (chip->probing) + if (chip->probing && chip->in_pm) err = 0; else if (!chip->shutdown) err = usb_autopm_get_interface(chip->pm_intf); @@ -673,7 +673,7 @@ int snd_usb_autoresume(struct snd_usb_audio *chip) void snd_usb_autosuspend(struct snd_usb_audio *chip) { down_read(&chip->shutdown_rwsem); - if (!chip->shutdown && !chip->probing) + if (!chip->shutdown && !chip->probing && !chip->in_pm) usb_autopm_put_interface(chip->pm_intf); up_read(&chip->shutdown_rwsem); } @@ -722,6 +722,8 @@ static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume) return 0; if (--chip->num_suspended_intf) return 0; + + chip->in_pm = 1; /* * ALSA leaves material resumption to user space * we just notify and restart the mixers @@ -737,6 +739,7 @@ static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume) chip->autosuspended = 0; err_out: + chip->in_pm = 0; return err; } diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h index caabe9b3af49..58d4ef14ff31 100644 --- a/sound/usb/usbaudio.h +++ b/sound/usb/usbaudio.h @@ -40,6 +40,7 @@ struct snd_usb_audio { struct rw_semaphore shutdown_rwsem; unsigned int shutdown:1; unsigned int probing:1; + unsigned int in_pm:1; unsigned int autosuspended:1; unsigned int txfr_quirk:1; /* Subframe boundaries on transfers */ |