Hi Alan,
On Tue, 28 Jul 2009 13:29:11 +0100 Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
>
> I need to look at the actual diff, but the combination looks completely
> bogus unless I'm misreading the fixup which is possible.
Below is the actual patch from the usb.current tree.
--
Cheers,
Stephen Rothwell sfr@xxxxxxxxxxxxxxxx
>From oliver@xxxxxxxxxx Sat Jul 18 15:45:44 2009
From: Oliver Neukum <oliver@xxxxxxxxxx>
Date: Sat, 18 Jul 2009 15:47:17 +0200
Subject: USB: fix usage count in usb serial generic open regarding autoresume
To: Matthew Garrett <mjg59@xxxxxxxxxxxxx>, Greg KH <greg@xxxxxxxxx>, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>, linux-usb@xxxxxxxxxxxxxxx
Message-ID: <200907181547.17813.oliver@xxxxxxxxxx>
Content-Disposition: inline
The resume handler has to resubmit the reading URBs if the device is
resumed while opened. But the open() method bumps the counter before
it resumes a device. The fix is to increment the counter only after
the resumption or if no resumption is attempted.
Signed-off-by: Oliver Neukum <oliver@xxxxxxxxxx>
Tested-by: Matthew Garrett <mjg@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/serial/usb-serial.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -214,15 +214,13 @@ static int serial_open (struct tty_struc
goto bailout_port_put;
}
- ++port->port.count;
-
/* set up our port structure making the tty driver
* remember our port object, and us it */
tty->driver_data = port;
tty_port_tty_set(&port->port, tty);
/* If the console is attached, the device is already open */
- if (port->port.count == 1 && !port->console) {
+ if (!port->port.count && !port->console) {
/* lock this module before we call it
* this may fail, which means we must bail out,
@@ -240,12 +238,16 @@ static int serial_open (struct tty_struc
if (retval)
goto bailout_module_put;
+ ++port->port.count;
+
/* only call the device specific open if this
* is the first time the port is opened */
retval = serial->type->open(tty, port, filp);
if (retval)
goto bailout_interface_put;
mutex_unlock(&serial->disc_mutex);
+ } else {
+ ++port->port.count;
}
mutex_unlock(&port->mutex);
/* Now do the correct tty layer semantics */
--
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