usb-serial: ftdi_sio: fix oops during autosuspend
This patch (as1550) fixes a bug in the usb-serial core that affects
the ftdi_sio driver and most likely others as well. The core
implements suspend and resume routines, but it doesn't store pointers
to those routines in the usb_driver structures that it registers,
even though it does set those drivers' supports_autosuspend flag. The
end result is that when one of these devices is autosuspended, we try
to call through a NULL pointer.
The patch fixes the problem by setting the suspend and resume method
pointers to the appropriate routines in the USB serial core, along
with the supports_autosuspend field, in each driver as it is
registered.
This should be back-ported to all the stable kernels that have the new
usb_serial_register_drivers() interface.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Frank Schäfer <schaefer.frank@gmx.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 906f06e..f7b263e 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -1336,7 +1336,6 @@
driver->description);
return -EINVAL;
}
- driver->usb_driver->supports_autosuspend = 1;
/* Add this device to our list of devices */
mutex_lock(&table_lock);
@@ -1371,7 +1370,7 @@
* @serial_drivers: NULL-terminated array of pointers to drivers to be registered
*
* Registers @udriver and all the drivers in the @serial_drivers array.
- * Automatically fills in the .no_dynamic_id field in @udriver and
+ * Automatically fills in the .no_dynamic_id and PM fields in @udriver and
* the .usb_driver field in each serial driver.
*/
int usb_serial_register_drivers(struct usb_driver *udriver,
@@ -1390,11 +1389,17 @@
* the serial drivers are registered, because the probe would
* simply fail for lack of a matching serial driver.
* Therefore save off udriver's id_table until we are all set.
+ *
+ * Suspend/resume support is implemented in the usb-serial core,
+ * so fill in the PM-related fields in udriver.
*/
saved_id_table = udriver->id_table;
udriver->id_table = NULL;
udriver->no_dynamic_id = 1;
+ udriver->supports_autosuspend = 1;
+ udriver->suspend = usb_serial_suspend;
+ udriver->resume = usb_serial_resume;
rc = usb_register(udriver);
if (rc)
return rc;