b43: Fix SDIO interrupt handler deadlock

We need to release the SDIO host before locking the driver mutex.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/sdio.c b/drivers/net/wireless/b43/sdio.c
index 2d337f1..0d3ac64 100644
--- a/drivers/net/wireless/b43/sdio.c
+++ b/drivers/net/wireless/b43/sdio.c
@@ -54,7 +54,12 @@
 	struct b43_sdio *sdio = sdio_get_drvdata(func);
 	struct b43_wldev *dev = sdio->irq_handler_opaque;
 
+	if (unlikely(b43_status(dev) < B43_STAT_STARTED))
+		return;
+
+	sdio_release_host(func);
 	sdio->irq_handler(dev);
+	sdio_claim_host(func);
 }
 
 int b43_sdio_request_irq(struct b43_wldev *dev,