char: lp: detach the device when parallel port is removed

When the parallel port is usb based and the lp attaches to it, we do
get /dev/lp0, but when we remove the usb device and the parallel port
is gone, we are still left with /dev/lp0.
Unregister the device properly in the detach routine based on the port
number it has connected to.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 7e207ff0f2fe6bbdc403ee2f44b0e8cb6d1bf9fd..e21ed4007d0fe4188074e9e17ef772d729fdc3ef 100644 (file)
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -976,6 +976,8 @@ static void lp_attach(struct parport *port)
 
 static void lp_detach(struct parport *port)
 {
+       int n;
+
        /* Write this some day. */
 #ifdef CONFIG_LP_CONSOLE
        if (console_registered == port) {
@@ -983,6 +985,14 @@ static void lp_detach(struct parport *port)
                console_registered = NULL;
        }
 #endif /* CONFIG_LP_CONSOLE */
+
+       for (n = 0; n < LP_NO; n++) {
+               if (port_num[n] == port->number) {
+                       port_num[n] = -1;
+                       device_destroy(lp_class, MKDEV(LP_MAJOR, n));
+                       parport_unregister_device(lp_table[n].dev);
+               }
+       }
 }
 
 static struct parport_driver lp_driver = {
@@ -1082,8 +1092,6 @@ static int __init lp_init_module(void)
 
 static void lp_cleanup_module(void)
 {
-       unsigned int offset;
-
        parport_unregister_driver(&lp_driver);
 
 #ifdef CONFIG_LP_CONSOLE
@@ -1091,13 +1099,6 @@ static void lp_cleanup_module(void)
 #endif
 
        unregister_chrdev(LP_MAJOR, "lp");
-       for (offset = 0; offset < LP_NO; offset++) {
-               if (lp_table[offset].dev == NULL)
-                       continue;
-               port_num[offset] = -1;
-               parport_unregister_device(lp_table[offset].dev);
-               device_destroy(lp_class, MKDEV(LP_MAJOR, offset));
-       }
        class_destroy(lp_class);
 }