USB: serial: mos7720: fix parallel probe

commit fde1faf872ed86d88e245191bc15a8e57368cd1c upstream.

A static usb-serial-driver structure that is used to initialise the
interrupt URB was modified during probe depending on the currently
probed device type, something which could break a parallel probe of a
device of a different type.

Fix this up by overriding the default completion callback for MCS7715
devices in attach() instead. We may want to use two usb-serial driver
instances for the two types later.

Fixes: fb088e335d78 ("USB: serial: add support for serial port on the
moschip 7715")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index 16db67f..ed46a76 100644 (file)
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -73,8 +73,6 @@ struct moschip_port {
 
 static int debug;
 
-static struct usb_serial_driver moschip7720_2port_driver;
-
 #define USB_VENDOR_ID_MOSCHIP          0x9710
 #define MOSCHIP_DEVICE_ID_7720         0x7720
 #define MOSCHIP_DEVICE_ID_7715         0x7715
@@ -1001,25 +999,6 @@ static void mos7720_bulk_out_data_callback(struct urb *urb)
        tty_kref_put(tty);
 }
 
-/*
- * mos77xx_probe
- *     this function installs the appropriate read interrupt endpoint callback
- *     depending on whether the device is a 7720 or 7715, thus avoiding costly
- *     run-time checks in the high-frequency callback routine itself.
- */
-static int mos77xx_probe(struct usb_serial *serial,
-                        const struct usb_device_id *id)
-{
-       if (id->idProduct == MOSCHIP_DEVICE_ID_7715)
-               moschip7720_2port_driver.read_int_callback =
-                       mos7715_interrupt_callback;
-       else
-               moschip7720_2port_driver.read_int_callback =
-                       mos7720_interrupt_callback;
-
-       return 0;
-}
-
 static int mos77xx_calc_num_ports(struct usb_serial *serial)
 {
        u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
@@ -2108,6 +2087,12 @@ static int mos7720_startup(struct usb_serial *serial)
                        tmp->interrupt_in_endpointAddress;
                serial->port[1]->interrupt_in_urb = NULL;
                serial->port[1]->interrupt_in_buffer = NULL;
+
+               if (serial->port[0]->interrupt_in_urb) {
+                       struct urb *urb = serial->port[0]->interrupt_in_urb;
+
+                       urb->complete = mos7715_interrupt_callback;
+               }
        }
 
 
@@ -2228,7 +2213,6 @@ static struct usb_serial_driver moschip7720_2port_driver = {
        .close                  = mos7720_close,
        .throttle               = mos7720_throttle,
        .unthrottle             = mos7720_unthrottle,
-       .probe                  = mos77xx_probe,
        .attach                 = mos7720_startup,
        .release                = mos7720_release,
        .ioctl                  = mos7720_ioctl,
@@ -2241,7 +2225,7 @@ static struct usb_serial_driver moschip7720_2port_driver = {
        .chars_in_buffer        = mos7720_chars_in_buffer,
        .break_ctl              = mos7720_break,
        .read_bulk_callback     = mos7720_bulk_in_callback,
-       .read_int_callback      = NULL  /* dynamically assigned in probe() */
+       .read_int_callback      = mos7720_interrupt_callback,
 };
 
 static int __init moschip7720_init(void)