b43legacy: Fix rfkill radio LED

This fixes Bug #9414 for b43legacy. This patch is the equivalent of one
submitted earlier for b43.

Since addition of the rfkill callback, the LED associated with the off
switch on the radio has not worked for several reasons:

(1) Essential data in the rfkill structure were missing.
(2) The rfkill structure was initialized after the LED initialization.
(3) There was a minor memory leak if the radio LED structure was inited.

Once the above problems were fixed, additional difficulties were noted:

(4) The radio LED was in the wrong state at startup.
(5) The radio switch had to be manipulated twice for each state change.
(6) A circular mutex locking situation existed.
(7) If rfkill-input is built as a module, it is not automatically loaded.

This patch fixes all of the above and removes a couple of sparse warnings.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 74 insertions, 59 deletions

diff --git a/drivers/net/wireless/b43legacy/rfkill.c b/drivers/net/wireless/b43legacy/rfkill.c
index b9d38a4f286d..520910fd5c45 100644
--- a/drivers/net/wireless/b43legacy/rfkill.c
+++ b/drivers/net/wireless/b43legacy/rfkill.c
@@ -26,6 +26,8 @@
 #include "radio.h"
 #include "b43legacy.h"
 
+#include <linux/kmod.h>
+
 
 /* Returns TRUE, if the radio is enabled in hardware. */
 static bool b43legacy_is_hw_radio_enabled(struct b43legacy_wldev *dev)
@@ -51,7 +53,10 @@ static void b43legacy_rfkill_poll(struct input_polled_dev *poll_dev)
         bool report_change = 0;
 
         mutex_lock(&wl->mutex);
-        B43legacy_WARN_ON(b43legacy_status(dev) < B43legacy_STAT_INITIALIZED);
+        if (unlikely(b43legacy_status(dev) < B43legacy_STAT_INITIALIZED)) {
+                mutex_unlock(&wl->mutex);
+                return;
+        }
         enabled = b43legacy_is_hw_radio_enabled(dev);
         if (unlikely(enabled != dev->radio_hw_enable)) {
                 dev->radio_hw_enable = enabled;
@@ -61,8 +66,12 @@ static void b43legacy_rfkill_poll(struct input_polled_dev *poll_dev)
         }
         mutex_unlock(&wl->mutex);
 
-        if (unlikely(report_change))
-                input_report_key(poll_dev->input, KEY_WLAN, enabled);
+        /* send the radio switch event to the system - note both a key press
+         * and a release are required */
+        if (unlikely(report_change)) {
+                input_report_key(poll_dev->input, KEY_WLAN, 1);
+                input_report_key(poll_dev->input, KEY_WLAN, 0);
+        }
 }
 
 /* Called when the RFKILL toggled in software.
@@ -71,13 +80,15 @@ static int b43legacy_rfkill_soft_toggle(void *data, enum rfkill_state state)
 {
         struct b43legacy_wldev *dev = data;
         struct b43legacy_wl *wl = dev->wl;
-        int err = 0;
+        int err = -EBUSY;
 
         if (!wl->rfkill.registered)
                 return 0;
 
         mutex_lock(&wl->mutex);
-        B43legacy_WARN_ON(b43legacy_status(dev) < B43legacy_STAT_INITIALIZED);
+        if (b43legacy_status(dev) < B43legacy_STAT_INITIALIZED)
+                goto out_unlock;
+        err = 0;
         switch (state) {
         case RFKILL_STATE_ON:
                 if (!dev->radio_hw_enable) {
@@ -103,11 +114,11 @@ out_unlock:
 
 char *b43legacy_rfkill_led_name(struct b43legacy_wldev *dev)
 {
-        struct b43legacy_wl *wl = dev->wl;
+        struct b43legacy_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 b43legacy_rfkill_init(struct b43legacy_wldev *dev)
@@ -116,53 +127,13 @@ void b43legacy_rfkill_init(struct b43legacy_wldev *dev)
         struct b43legacy_rfkill *rfk = &(wl->rfkill);
         int err;
 
-        if (rfk->rfkill) {
-                err = rfkill_register(rfk->rfkill);
-                if (err) {
-                        b43legacywarn(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) {
-                        b43legacywarn(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 b43legacy_rfkill_exit(struct b43legacy_wldev *dev)
-{
-        struct b43legacy_rfkill *rfk = &(dev->wl->rfkill);
-
-        if (rfk->poll_dev)
-                input_unregister_polled_device(rfk->poll_dev);
-        if (rfk->rfkill)
-                rfkill_unregister(rfk->rfkill);
-}
-
-void b43legacy_rfkill_alloc(struct b43legacy_wldev *dev)
-{
-        struct b43legacy_wl *wl = dev->wl;
-        struct b43legacy_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),
                  "b43legacy-%s", wiphy_name(wl->hw->wiphy));
-
-        rfk->rfkill = rfkill_allocate(dev->dev->dev, RFKILL_TYPE_WLAN);
-        if (!rfk->rfkill) {
-                b43legacywarn(wl, "Failed to allocate RF-kill button\n");
-                return;
-        }
         rfk->rfkill->name = rfk->name;
         rfk->rfkill->state = RFKILL_STATE_ON;
         rfk->rfkill->data = dev;
@@ -170,20 +141,64 @@ void b43legacy_rfkill_alloc(struct b43legacy_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 = b43legacy_rfkill_poll;
-                rfk->poll_dev->poll_interval = 1000; /* msecs */
-        } else
-                b43legacywarn(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 = b43legacy_rfkill_poll;
+        rfk->poll_dev->poll_interval = 1000; /* msecs */
+
+        rfk->poll_dev->input->name = rfk->name;
+        rfk->poll_dev->input->id.bustype = BUS_HOST;
+        rfk->poll_dev->input->id.vendor = dev->dev->bus->boardinfo.vendor;
+        rfk->poll_dev->input->evbit[0] = BIT(EV_KEY);
+        set_bit(KEY_WLAN, rfk->poll_dev->input->keybit);
+
+        err = rfkill_register(rfk->rfkill);
+        if (err)
+                goto err_free_polldev;
+
+#ifdef CONFIG_RFKILL_INPUT_MODULE
+        /* B43legacy RF-kill isn't useful without the rfkill-input subsystem.
+         * Try to load the module. */
+        err = request_module("rfkill-input");
+        if (err)
+                b43legacywarn(wl, "Failed to load the rfkill-input module."
+                        "The built-in radio LED will not work.\n");
+#endif /* CONFIG_RFKILL_INPUT */
+
+        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;
+        b43legacywarn(wl, "RF-kill button init failed\n");
 }
 
-void b43legacy_rfkill_free(struct b43legacy_wldev *dev)
+void b43legacy_rfkill_exit(struct b43legacy_wldev *dev)
 {
         struct b43legacy_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);
         rfk->rfkill = NULL;
 }
+