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ALSA: usb-audio: Avoid autopm calls after disconnection 

Add a similar protection against the disconnection race and the
invalid use of usb instance after disconnection, as well as we've done
for the USB audio PCM.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=51201

Reviewd-by: Clemens Ladisch <clemens@ladisch.de>
Tested-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
wifi-calibration
Takashi Iwai 2012-12-03 11:12:46 +01:00
parent 467b103505
commit 59866da9e4
1 changed files with 22 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
sound/usb/midi.c
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@ -116,6 +116,7 @@ struct snd_usb_midi {
struct list_head list;
struct timer_list error_timer;
spinlock_t disc_lock;
struct rw_semaphore disc_rwsem;
struct mutex mutex;
u32 usb_id;
int next_midi_device;
@ -1038,6 +1039,12 @@ static void substream_open(struct snd_rawmidi_substream *substream, int open)
struct snd_usb_midi* umidi = substream->rmidi->private_data;
struct snd_kcontrol *ctl;
down_read(&umidi->disc_rwsem);
if (umidi->disconnected) {
up_read(&umidi->disc_rwsem);
return;
}
mutex_lock(&umidi->mutex);
if (open) {
if (umidi->opened++ == 0 && umidi->roland_load_ctl) {
@ -1056,6 +1063,7 @@ static void substream_open(struct snd_rawmidi_substream *substream, int open)
}
}
mutex_unlock(&umidi->mutex);
up_read(&umidi->disc_rwsem);
}
static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream)
@ -1076,8 +1084,15 @@ static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream)
snd_BUG();
return -ENXIO;
}
down_read(&umidi->disc_rwsem);
if (umidi->disconnected) {
up_read(&umidi->disc_rwsem);
return -ENODEV;
}
err = usb_autopm_get_interface(umidi->iface);
port->autopm_reference = err >= 0;
up_read(&umidi->disc_rwsem);
if (err < 0 && err != -EACCES)
return -EIO;
substream->runtime->private_data = port;
@ -1092,8 +1107,10 @@ static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream)
struct usbmidi_out_port *port = substream->runtime->private_data;
substream_open(substream, 0);
if (port->autopm_reference)
down_read(&umidi->disc_rwsem);
if (!umidi->disconnected && port->autopm_reference)
usb_autopm_put_interface(umidi->iface);
up_read(&umidi->disc_rwsem);
return 0;
}
@ -1403,9 +1420,12 @@ void snd_usbmidi_disconnect(struct list_head* p)
* a timer may submit an URB. To reliably break the cycle
* a flag under lock must be used
*/
down_write(&umidi->disc_rwsem);
spin_lock_irq(&umidi->disc_lock);
umidi->disconnected = 1;
spin_unlock_irq(&umidi->disc_lock);
up_write(&umidi->disc_rwsem);
for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
struct snd_usb_midi_endpoint* ep = &umidi->endpoints[i];
if (ep->out)
@ -2117,6 +2137,7 @@ int snd_usbmidi_create(struct snd_card *card,
umidi->usb_protocol_ops = &snd_usbmidi_standard_ops;
init_timer(&umidi->error_timer);
spin_lock_init(&umidi->disc_lock);
init_rwsem(&umidi->disc_rwsem);
mutex_init(&umidi->mutex);
umidi->usb_id = USB_ID(le16_to_cpu(umidi->dev->descriptor.idVendor),
le16_to_cpu(umidi->dev->descriptor.idProduct));