Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6

1 files changed, 16 insertions, 5 deletions

diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
index a7b5cb0c2753..224e9853c480 100644
--- a/drivers/net/wireless/libertas/if_sdio.c
+++ b/drivers/net/wireless/libertas/if_sdio.c
@@ -907,7 +907,7 @@ static void if_sdio_interrupt(struct sdio_func *func)
 	card = sdio_get_drvdata(func);
 
 	cause = sdio_readb(card->func, IF_SDIO_H_INT_STATUS, &ret);
-	if (ret)
+	if (ret || !cause)
 		goto out;
 
 	lbs_deb_sdio("interrupt: 0x%X\n", (unsigned)cause);
@@ -1008,10 +1008,6 @@ static int if_sdio_probe(struct sdio_func *func,
 	if (ret)
 		goto release;
 
-	ret = sdio_claim_irq(func, if_sdio_interrupt);
-	if (ret)
-		goto disable;
-
 	/* For 1-bit transfers to the 8686 model, we need to enable the
 	 * interrupt flag in the CCCR register. Set the MMC_QUIRK_LENIENT_FN0
 	 * bit to allow access to non-vendor registers. */
@@ -1083,6 +1079,21 @@ static int if_sdio_probe(struct sdio_func *func,
 		card->rx_unit = 0;
 
 	/*
+	 * Set up the interrupt handler late.
+	 *
+	 * If we set it up earlier, the (buggy) hardware generates a spurious
+	 * interrupt, even before the interrupt has been enabled, with
+	 * CCCR_INTx = 0.
+	 *
+	 * We register the interrupt handler late so that we can handle any
+	 * spurious interrupts, and also to avoid generation of that known
+	 * spurious interrupt in the first place.
+	 */
+	ret = sdio_claim_irq(func, if_sdio_interrupt);
+	if (ret)
+		goto disable;
+
+	/*
 	 * Enable interrupts now that everything is set up
 	 */
 	sdio_writeb(func, 0x0f, IF_SDIO_H_INT_MASK, &ret);