Input: db9 - store object at correct index

The variable i is used to check the port to attach to and we are
supposed to save the reference of struct db9 in the location given by
db9_base[i]. But after finding out the index, i is getting modified again
so we saved in a wrong index.
While at it mark db9_base[i] as NULL after it is freed.

Fixes: 2260c419b52b ("Input: db9 - use parallel port device model")
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/drivers/input/joystick/db9.c b/drivers/input/joystick/db9.c
index cf1f602e0f0a..932d07307454 100644
--- a/drivers/input/joystick/db9.c
+++ b/drivers/input/joystick/db9.c
@@ -560,25 +560,25 @@ static void db9_attach(struct parport *pp)
         const struct db9_mode_data *db9_mode;
         struct pardevice *pd;
         struct input_dev *input_dev;
-        int i, j;
+        int i, j, port_idx;
         int mode;
         struct pardev_cb db9_parport_cb;
 
-        for (i = 0; i < DB9_MAX_PORTS; i++) {
-                if (db9_cfg[i].nargs == 0 ||
-                    db9_cfg[i].args[DB9_ARG_PARPORT] < 0)
+        for (port_idx = 0; port_idx < DB9_MAX_PORTS; port_idx++) {
+                if (db9_cfg[port_idx].nargs == 0 ||
+                    db9_cfg[port_idx].args[DB9_ARG_PARPORT] < 0)
                         continue;
 
-                if (db9_cfg[i].args[DB9_ARG_PARPORT] == pp->number)
+                if (db9_cfg[port_idx].args[DB9_ARG_PARPORT] == pp->number)
                         break;
         }
 
-        if (i == DB9_MAX_PORTS) {
+        if (port_idx == DB9_MAX_PORTS) {
                 pr_debug("Not using parport%d.\n", pp->number);
                 return;
         }
 
-        mode = db9_cfg[i].args[DB9_ARG_MODE];
+        mode = db9_cfg[port_idx].args[DB9_ARG_MODE];
 
         if (mode < 1 || mode >= DB9_MAX_PAD || !db9_modes[mode].n_buttons) {
                 printk(KERN_ERR "db9.c: Bad device type %d\n", mode);
@@ -594,7 +594,7 @@ static void db9_attach(struct parport *pp)
 
         db9_parport_cb.flags = PARPORT_FLAG_EXCL;
 
-        pd = parport_register_dev_model(pp, "db9", &db9_parport_cb, i);
+        pd = parport_register_dev_model(pp, "db9", &db9_parport_cb, port_idx);
         if (!pd) {
                 printk(KERN_ERR "db9.c: parport busy already - lp.o loaded?\n");
                 return;
@@ -649,7 +649,7 @@ static void db9_attach(struct parport *pp)
                         goto err_free_dev;
         }
 
-        db9_base[i] = db9;
+        db9_base[port_idx] = db9;
         return;
 
  err_free_dev:
@@ -676,6 +676,7 @@ static void db9_detach(struct parport *port)
                 return;
 
         db9 = db9_base[i];
+        db9_base[i] = NULL;
 
         for (i = 0; i < min(db9_modes[db9->mode].n_pads, DB9_MAX_DEVICES); i++)
                 input_unregister_device(db9->dev[i]);