[ 44/91] usb-serial: ftdi_sio: fix oops during autosuspend
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-05-27 01:17:39
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3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern <stern@rowland.harvard.edu> commit 5cbe61c5aff0a8ada691eb8b07dbfb55c303f640 upstream. 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 Sch��fer <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/usb/serial/usb-serial.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c@@ -1338,7 +1338,6 @@ static int usb_serial_register(struct us driver->description); return -EINVAL; } - driver->usb_driver->supports_autosuspend = 1; /* Add this device to our list of devices */ mutex_lock(&table_lock);
@@ -1373,7 +1372,7 @@ static void usb_serial_deregister(struct * @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,
@@ -1392,11 +1391,17 @@ int usb_serial_register_drivers(struct u * 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;