b43: Fix possible MMIO access while device is down

This fixes a possible MMIO access while the device is still down
from a suspend cycle. MMIO accesses with the device powered down
may cause crashes on certain devices.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/net/wireless/b43/leds.c b/drivers/net/wireless/b43/leds.c
index 36a9c42df835..76f4c7bad8b8 100644
--- a/drivers/net/wireless/b43/leds.c
+++ b/drivers/net/wireless/b43/leds.c
@@ -72,6 +72,9 @@ static void b43_led_brightness_set(struct led_classdev *led_dev,
         struct b43_wldev *dev = led->dev;
         bool radio_enabled;
 
+        if (unlikely(b43_status(dev) < B43_STAT_INITIALIZED))
+                return;
+
         /* Checking the radio-enabled status here is slightly racy,
          * but we want to avoid the locking overhead and we don't care
          * whether the LED has the wrong state for a second. */