---

yaml
---
r: 253397
b: refs/heads/master
c: d2ac49f
h: refs/heads/master
i:
  253395: 0455ccd
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 59e7e7078d6c2c6294caf454c6e3695f9d3e46a2
+refs/heads/master: d2ac49fe3c7c4730323c1042fb53a2e008643b6a

trunk/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. */
@@ -1082,6 +1078,21 @@ static int if_sdio_probe(struct sdio_func *func,
 	else
 		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
 	 */