diff options
| author | Johan Hovold <jhovold@gmail.com> | 2014-05-26 19:23:15 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-07-11 13:33:40 +0100 |
| commit | 85296fc41103b19ff46fdb7392fb87fd95c91669 (patch) | |
| tree | 63bb6731d560bea17c509107e88bcd8045de0081 /drivers/usb | |
| parent | 0985cf0a59c203045a80abfaa5647285673b23ba (diff) | |
USB: usb_wwan: fix write and suspend race
commit 170fad9e22df0063eba0701adb966786d7a4ec5a upstream.
Fix race between write() and suspend() which could lead to writes being
dropped (or I/O while suspended) if the device is runtime suspended
while a write request is being processed.
Specifically, suspend() releases the susp_lock after determining the
device is idle but before setting the suspended flag, thus leaving a
window where a concurrent write() can submit an urb.
Fixes: 383cedc3bb43 ("USB: serial: full autosuspend support for the
option driver")
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/serial/usb_wwan.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c index 7ccff6c16c44..bb2a713dda93 100644 --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -647,22 +647,19 @@ EXPORT_SYMBOL(usb_wwan_release); int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) { struct usb_wwan_intf_private *intfdata = serial->private; - int b; dbg("%s entered", __func__); + spin_lock_irq(&intfdata->susp_lock); if (PMSG_IS_AUTO(message)) { - spin_lock_irq(&intfdata->susp_lock); - b = intfdata->in_flight; - spin_unlock_irq(&intfdata->susp_lock); - - if (b) + if (intfdata->in_flight) { + spin_unlock_irq(&intfdata->susp_lock); return -EBUSY; + } } - - spin_lock_irq(&intfdata->susp_lock); intfdata->suspended = 1; spin_unlock_irq(&intfdata->susp_lock); + stop_read_write_urbs(serial); return 0; |