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| author | David Herrmann <dh.herrmann@googlemail.com> | 2011-10-26 11:13:13 +0200 |
|---|---|---|
| committer | Gustavo F. Padovan <padovan@profusion.mobi> | 2011-10-31 17:51:37 -0200 |
| commit | fc501ad7a10a356819505b1e526079d47fdebc2c (patch) | |
| tree | 3eae55cf4945ac834e40c5cde95555b610084ded /drivers/bluetooth/bcm203x.c | |
| parent | 0ba22bb258341783939ed07bf7e7a9d92f3b0edf (diff) | |
| download | lwn-fc501ad7a10a356819505b1e526079d47fdebc2c.tar.gz lwn-fc501ad7a10a356819505b1e526079d47fdebc2c.zip | |
Bluetooth: bcm203x: Fix race condition on disconnect
When disconnecting a bcm203x device we kill and destroy the usb-urb, however,
there might still be a pending work-structure which resubmits the now invalid
urb. To avoid this race condition, we simply set a shutdown-flag and
synchronously kill the worker first.
This also adds a comment to all schedule_work()s, as it is really not clear
that they are used as replacement for short timers (which can be seen in the git
history).
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Diffstat (limited to 'drivers/bluetooth/bcm203x.c')
| -rw-r--r-- | drivers/bluetooth/bcm203x.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/bluetooth/bcm203x.c b/drivers/bluetooth/bcm203x.c index 8b1b643a519b..ec743c2ddf9d 100644 --- a/drivers/bluetooth/bcm203x.c +++ b/drivers/bluetooth/bcm203x.c @@ -24,6 +24,7 @@ #include <linux/module.h> +#include <linux/atomic.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/slab.h> @@ -65,6 +66,7 @@ struct bcm203x_data { unsigned long state; struct work_struct work; + atomic_t shutdown; struct urb *urb; unsigned char *buffer; @@ -97,6 +99,7 @@ static void bcm203x_complete(struct urb *urb) data->state = BCM203X_SELECT_MEMORY; + /* use workqueue to have a small delay */ schedule_work(&data->work); break; @@ -155,6 +158,9 @@ static void bcm203x_work(struct work_struct *work) struct bcm203x_data *data = container_of(work, struct bcm203x_data, work); + if (atomic_read(&data->shutdown)) + return; + if (usb_submit_urb(data->urb, GFP_ATOMIC) < 0) BT_ERR("Can't submit URB"); } @@ -243,6 +249,7 @@ static int bcm203x_probe(struct usb_interface *intf, const struct usb_device_id usb_set_intfdata(intf, data); + /* use workqueue to have a small delay */ schedule_work(&data->work); return 0; @@ -254,6 +261,9 @@ static void bcm203x_disconnect(struct usb_interface *intf) BT_DBG("intf %p", intf); + atomic_inc(&data->shutdown); + cancel_work_sync(&data->work); + usb_kill_urb(data->urb); usb_set_intfdata(intf, NULL); |