USB: fix mos7840 problem with minor numbers

This patch fixes a problem with any mos7840 device where the use of the field "minor" before it is
initialised results in all the devices being overlaid in memory (minor = 0 for all instances)

Contributed by: Phillip Branch

Signed-off-by: Tony Cook <tony-cook@bigpond.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 567985b7013e5ccde223b4edf70385a170da527f..499b7b82a0ec1196a630ed86c832f3a7128cf55c 100644 (file)
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -38,7 +38,7 @@
 /*
  * Version Information
  */
-#define DRIVER_VERSION "1.3.1"
+#define DRIVER_VERSION "1.3.2"
 #define DRIVER_DESC "Moschip 7840/7820 USB Serial Driver"
 
 /*
@@ -2484,9 +2484,14 @@ static int mos7840_startup(struct usb_serial *serial)
                mos7840_set_port_private(serial->port[i], mos7840_port);
                spin_lock_init(&mos7840_port->pool_lock);
 
-               mos7840_port->port_num = ((serial->port[i]->number -
-                                          (serial->port[i]->serial->minor)) +
-                                         1);
+               /* minor is not initialised until later by
+                * usb-serial.c:get_free_serial() and cannot therefore be used
+                * to index device instances */
+               mos7840_port->port_num = i + 1;
+               dbg ("serial->port[i]->number = %d", serial->port[i]->number);
+               dbg ("serial->port[i]->serial->minor = %d", serial->port[i]->serial->minor);
+               dbg ("mos7840_port->port_num = %d", mos7840_port->port_num);
+               dbg ("serial->minor = %d", serial->minor);
 
                if (mos7840_port->port_num == 1) {
                        mos7840_port->SpRegOffset = 0x0;
@@ -2697,13 +2702,16 @@ static void mos7840_shutdown(struct usb_serial *serial)
 
        for (i = 0; i < serial->num_ports; ++i) {
                mos7840_port = mos7840_get_port_private(serial->port[i]);
-               spin_lock_irqsave(&mos7840_port->pool_lock, flags);
-               mos7840_port->zombie = 1;
-               spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
-               usb_kill_urb(mos7840_port->control_urb);
-               kfree(mos7840_port->ctrl_buf);
-               kfree(mos7840_port->dr);
-               kfree(mos7840_port);
+               dbg ("mos7840_port %d = %p", i, mos7840_port);
+               if (mos7840_port) {
+                       spin_lock_irqsave(&mos7840_port->pool_lock, flags);
+                       mos7840_port->zombie = 1;
+                       spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
+                       usb_kill_urb(mos7840_port->control_urb);
+                       kfree(mos7840_port->ctrl_buf);
+                       kfree(mos7840_port->dr);
+                       kfree(mos7840_port);
+               }
                mos7840_set_port_private(serial->port[i], NULL);
        }