b43: Rewrite and fix rfkill init

The rfkill subsystem doesn't like code like that
rfkill_allocate();
rfkill_register();
rfkill_unregister();
rfkill_register(); /* <- This will crash */

This sequence happens with
modprobe b43
ifconfig wlanX up
ifconfig wlanX down
ifconfig wlanX up

Fix this by always re-allocating the rfkill stuff before register.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 55 insertions, 80 deletions

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 5058e60e5703..c9778c6cf2e8 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -3661,7 +3661,6 @@ static int b43_setup_modes(struct b43_wldev *dev,
 
 static void b43_wireless_core_detach(struct b43_wldev *dev)
 {
-        b43_rfkill_free(dev);
         /* We release firmware that late to not be required to re-request
          * is all the time when we reinit the core. */
         b43_release_firmware(dev);
@@ -3747,7 +3746,6 @@ static int b43_wireless_core_attach(struct b43_wldev *dev)
         if (!wl->current_dev)
                 wl->current_dev = dev;
         INIT_WORK(&dev->restart_work, b43_chip_reset);
-        b43_rfkill_alloc(dev);
 
         b43_radio_turn_off(dev, 1);
         b43_switch_analog(dev, 0);
diff --git a/drivers/net/wireless/b43/rfkill.c b/drivers/net/wireless/b43/rfkill.c
index 456930ffef2d..9b1f905ffbf4 100644
--- a/drivers/net/wireless/b43/rfkill.c
+++ b/drivers/net/wireless/b43/rfkill.c
@@ -47,18 +47,21 @@ static void b43_rfkill_poll(struct input_polled_dev *poll_dev)
         struct b43_wldev *dev = poll_dev->private;
         struct b43_wl *wl = dev->wl;
         bool enabled;
+        bool report_change = 0;
 
         mutex_lock(&wl->mutex);
         B43_WARN_ON(b43_status(dev) < B43_STAT_INITIALIZED);
         enabled = b43_is_hw_radio_enabled(dev);
         if (unlikely(enabled != dev->radio_hw_enable)) {
                 dev->radio_hw_enable = enabled;
+                report_change = 1;
                 b43info(wl, "Radio hardware status changed to %s\n",
                         enabled ? "ENABLED" : "DISABLED");
-                mutex_unlock(&wl->mutex);
+        }
+        mutex_unlock(&wl->mutex);
+
+        if (unlikely(report_change))
                 input_report_key(poll_dev->input, KEY_WLAN, enabled);
-        } else
-                mutex_unlock(&wl->mutex);
 }
 
 /* Called when the RFKILL toggled in software. */
@@ -68,18 +71,11 @@ static int b43_rfkill_soft_toggle(void *data, enum rfkill_state state)
         struct b43_wl *wl = dev->wl;
         int err = 0;
 
-        /* When RFKILL is registered, it will call back into this callback.
-         * wl->mutex will already be locked when this happens.
-         * So first trylock. On contention check if we are in initialization.
-         * Silently return if that happens to avoid a deadlock. */
-        if (mutex_trylock(&wl->mutex) == 0) {
-                if (b43_status(dev) < B43_STAT_INITIALIZED)
-                        return 0;
-                mutex_lock(&wl->mutex);
-        }
-        if (b43_status(dev) < B43_STAT_INITIALIZED)
-                goto out_unlock;
+        if (!wl->rfkill.registered)
+                return 0;
 
+        mutex_lock(&wl->mutex);
+        B43_WARN_ON(b43_status(dev) < B43_STAT_INITIALIZED);
         switch (state) {
         case RFKILL_STATE_ON:
                 if (!dev->radio_hw_enable) {
@@ -104,11 +100,11 @@ out_unlock:
 
 char * b43_rfkill_led_name(struct b43_wldev *dev)
 {
-        struct b43_wl *wl = dev->wl;
+        struct b43_rfkill *rfk = &(dev->wl->rfkill);
 
-        if (!wl->rfkill.rfkill)
+        if (!rfk->registered)
                 return NULL;
-        return rfkill_get_led_name(wl->rfkill.rfkill);
+        return rfkill_get_led_name(rfk->rfkill);
 }
 
 void b43_rfkill_init(struct b43_wldev *dev)
@@ -117,53 +113,13 @@ void b43_rfkill_init(struct b43_wldev *dev)
         struct b43_rfkill *rfk = &(wl->rfkill);
         int err;
 
-        if (rfk->rfkill) {
-                err = rfkill_register(rfk->rfkill);
-                if (err) {
-                        b43warn(wl, "Failed to register RF-kill button\n");
-                        goto err_free_rfk;
-                }
-        }
-        if (rfk->poll_dev) {
-                err = input_register_polled_device(rfk->poll_dev);
-                if (err) {
-                        b43warn(wl, "Failed to register RF-kill polldev\n");
-                        goto err_free_polldev;
-                }
-        }
-
-        return;
-err_free_rfk:
-        rfkill_free(rfk->rfkill);
-        rfk->rfkill = NULL;
-err_free_polldev:
-        input_free_polled_device(rfk->poll_dev);
-        rfk->poll_dev = NULL;
-}
-
-void b43_rfkill_exit(struct b43_wldev *dev)
-{
-        struct b43_rfkill *rfk = &(dev->wl->rfkill);
-
-        if (rfk->poll_dev)
-                input_unregister_polled_device(rfk->poll_dev);
-        if (rfk->rfkill)
-                rfkill_unregister(rfk->rfkill);
-}
-
-void b43_rfkill_alloc(struct b43_wldev *dev)
-{
-        struct b43_wl *wl = dev->wl;
-        struct b43_rfkill *rfk = &(wl->rfkill);
+        rfk->registered = 0;
 
+        rfk->rfkill = rfkill_allocate(dev->dev->dev, RFKILL_TYPE_WLAN);
+        if (!rfk->rfkill)
+                goto out_error;
         snprintf(rfk->name, sizeof(rfk->name),
                  "b43-%s", wiphy_name(wl->hw->wiphy));
-
-        rfk->rfkill = rfkill_allocate(dev->dev->dev, RFKILL_TYPE_WLAN);
-        if (!rfk->rfkill) {
-                b43warn(wl, "Failed to allocate RF-kill button\n");
-                return;
-        }
         rfk->rfkill->name = rfk->name;
         rfk->rfkill->state = RFKILL_STATE_ON;
         rfk->rfkill->data = dev;
@@ -171,18 +127,45 @@ void b43_rfkill_alloc(struct b43_wldev *dev)
         rfk->rfkill->user_claim_unsupported = 1;
 
         rfk->poll_dev = input_allocate_polled_device();
-        if (rfk->poll_dev) {
-                rfk->poll_dev->private = dev;
-                rfk->poll_dev->poll = b43_rfkill_poll;
-                rfk->poll_dev->poll_interval = 1000; /* msecs */
-        } else
-                b43warn(wl, "Failed to allocate RF-kill polldev\n");
+        if (!rfk->poll_dev)
+                goto err_free_rfk;
+        rfk->poll_dev->private = dev;
+        rfk->poll_dev->poll = b43_rfkill_poll;
+        rfk->poll_dev->poll_interval = 1000; /* msecs */
+
+        err = rfkill_register(rfk->rfkill);
+        if (err)
+                goto err_free_polldev;
+        err = input_register_polled_device(rfk->poll_dev);
+        if (err)
+                goto err_unreg_rfk;
+
+        rfk->registered = 1;
+
+        return;
+err_unreg_rfk:
+        rfkill_unregister(rfk->rfkill);
+err_free_polldev:
+        input_free_polled_device(rfk->poll_dev);
+        rfk->poll_dev = NULL;
+err_free_rfk:
+        rfkill_free(rfk->rfkill);
+        rfk->rfkill = NULL;
+out_error:
+        rfk->registered = 0;
+        b43warn(wl, "RF-kill button init failed\n");
 }
 
-void b43_rfkill_free(struct b43_wldev *dev)
+void b43_rfkill_exit(struct b43_wldev *dev)
 {
         struct b43_rfkill *rfk = &(dev->wl->rfkill);
 
+        if (!rfk->registered)
+                return;
+        rfk->registered = 0;
+
+        input_unregister_polled_device(rfk->poll_dev);
+        rfkill_unregister(rfk->rfkill);
         input_free_polled_device(rfk->poll_dev);
         rfk->poll_dev = NULL;
         rfkill_free(rfk->rfkill);
diff --git a/drivers/net/wireless/b43/rfkill.h b/drivers/net/wireless/b43/rfkill.h
index 29544e8c9e5f..adacf936d815 100644
--- a/drivers/net/wireless/b43/rfkill.h
+++ b/drivers/net/wireless/b43/rfkill.h
@@ -15,14 +15,14 @@ struct b43_rfkill {
         struct rfkill *rfkill;
         /* The poll device for the RFKILL input button */
         struct input_polled_dev *poll_dev;
+        /* Did initialization succeed? Used for freeing. */
+        bool registered;
         /* The unique name of this rfkill switch */
-        char name[32];
+        char name[sizeof("b43-phy4294967295")];
 };
 
-/* All the init functions return void, because we are not interested
+/* The init function returns void, because we are not interested
  * in failing the b43 init process when rfkill init failed. */
-void b43_rfkill_alloc(struct b43_wldev *dev);
-void b43_rfkill_free(struct b43_wldev *dev);
 void b43_rfkill_init(struct b43_wldev *dev);
 void b43_rfkill_exit(struct b43_wldev *dev);
 
@@ -36,12 +36,6 @@ struct b43_rfkill {
         /* empty */
 };
 
-static inline void b43_rfkill_alloc(struct b43_wldev *dev)
-{
-}
-static inline void b43_rfkill_free(struct b43_wldev *dev)
-{
-}
 static inline void b43_rfkill_init(struct b43_wldev *dev)
 {
 }