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| author | Johan Hovold <jhovold@gmail.com> | 2014-05-26 19:23:15 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-30 20:11:56 -0700 |
| commit | 5a77e53bb1cb996391ab1feb898b6ffb0657f96f (patch) | |
| tree | c43ffb9ce743efafecb6adf3c3200d4dec258a4d /drivers/usb/serial | |
| parent | 2f59a10cb390aaa74dda48ca73214d8ce52d3c2b (diff) | |
| download | lwn-5a77e53bb1cb996391ab1feb898b6ffb0657f96f.tar.gz lwn-5a77e53bb1cb996391ab1feb898b6ffb0657f96f.zip | |
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>
Diffstat (limited to 'drivers/usb/serial')
| -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 112693a4100b..2b8f02696c00 100644 --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -579,20 +579,17 @@ static void stop_read_write_urbs(struct usb_serial *serial) int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) { struct usb_wwan_intf_private *intfdata = serial->private; - int b; + 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; |