102 lines
3.3 KiB
Diff
102 lines
3.3 KiB
Diff
From: Takashi Iwai <tiwai@suse.de>
|
|
Date: Mon, 3 Dec 2012 11:12:46 +0100
|
|
Subject: [1/2] ALSA: usb-audio: Avoid autopm calls after disconnection
|
|
|
|
commit 59866da9e4ae54819e3c4e0a8f426bdb0c2ef993 upstream.
|
|
|
|
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>
|
|
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
---
|
|
sound/usb/midi.c | 23 ++++++++++++++++++++++-
|
|
1 file changed, 22 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/sound/usb/midi.c b/sound/usb/midi.c
|
|
index eeefbce..c0054ee 100644
|
|
--- a/sound/usb/midi.c
|
|
+++ b/sound/usb/midi.c
|
|
@@ -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));
|