@@ -664,17 +664,15 @@ int usb_wwan_resume(struct usb_serial *serial)
}
}
+ spin_lock_irq(&intfdata->susp_lock);
for (i = 0; i < serial->num_ports; i++) {
/* walk all ports */
port = serial->port[i];
portdata = usb_get_serial_port_data(port);
/* skip closed ports */
- spin_lock_irq(&intfdata->susp_lock);
- if (!portdata || !portdata->opened) {
- spin_unlock_irq(&intfdata->susp_lock);
+ if (!portdata || !portdata->opened)
continue;
- }
for (j = 0; j < N_IN_URB; j++) {
urb = portdata->in_urbs[j];
@@ -687,9 +685,7 @@ int usb_wwan_resume(struct usb_serial *serial)
}
}
play_delayed(port);
- spin_unlock_irq(&intfdata->susp_lock);
}
- spin_lock_irq(&intfdata->susp_lock);
intfdata->suspended = 0;
spin_unlock_irq(&intfdata->susp_lock);
err_out:
This is a note to let you know that I have just added a patch titled USB: usb_wwan: fix race between write and resume to the linux-3.11.y-queue branch of the 3.11.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-3.11.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 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 69d4ec981cfbbe408cca6aa751a64c149b854ee6 Mon Sep 17 00:00:00 2001 From: xiao jin <jin.xiao@intel.com> Date: Mon, 26 May 2014 19:23:14 +0200 Subject: USB: usb_wwan: fix race between write and resume commit d9e93c08d8d985e5ef89436ebc9f4aad7e31559f upstream. We find a race between write and resume. usb_wwan_resume run play_delayed() and spin_unlock, but intfdata->suspended still is not set to zero. At this time usb_wwan_write is called and anchor the urb to delay list. Then resume keep running but the delayed urb have no chance to be commit until next resume. If the time of next resume is far away, tty will be blocked in tty_wait_until_sent during time. The race also can lead to writes being reordered. This patch put play_Delayed and intfdata->suspended together in the spinlock, it's to avoid the write race during resume. Fixes: 383cedc3bb43 ("USB: serial: full autosuspend support for the option driver") Signed-off-by: xiao jin <jin.xiao@intel.com> Signed-off-by: Zhang, Qi1 <qi1.zhang@intel.com> Reviewed-by: David Cohen <david.a.cohen@linux.intel.com> Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/usb/serial/usb_wwan.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) -- 1.9.1