@@ -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));
This is a note to let you know that I have just added a patch titled ALSA: usb-audio: Avoid autopm calls after disconnection to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From ca1ff9bc982d25d413f9613837184d49397e228d Mon Sep 17 00:00:00 2001 From: Takashi Iwai <tiwai@suse.de> Date: Mon, 3 Dec 2012 11:12:46 +0100 Subject: [PATCH] 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> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- sound/usb/midi.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) -- 1.7.9.5