mmc: omap_hsmmc: use threaded irq handler for card-detect.

As the card-detect irq handler just schedules work to be done by a
thread, we can use request_threaded_irq to do much of the work for
us.  This means that interrupts which arrive by handle_nested_irq
actually work.

Reviewed-by: Felipe Balbi <balbi@ti.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Kishore Kadiyala <kishorek.kadiyala@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/omap_hsmmc.c

@@ -24,7 +24,6 @@
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/platform_device.h>
-#include <linux/workqueue.h>
 #include <linux/timer.h>
 #include <linux/clk.h>
 #include <linux/mmc/host.h>
@@ -162,7 +161,6 @@ struct omap_hsmmc_host {
 	 */
 	struct	regulator	*vcc;
 	struct	regulator	*vcc_aux;
-	struct	work_struct	mmc_carddetect_work;
 	void	__iomem		*base;
 	resource_size_t		mapbase;
 	spinlock_t		irq_lock; /* Prevent races with irq handler */
@@ -1279,17 +1277,16 @@ static void omap_hsmmc_protect_card(struct omap_hsmmc_host *host)
 }
 
 /*
- * Work Item to notify the core about card insertion/removal
+ * irq handler to notify the core about card insertion/removal
  */
-static void omap_hsmmc_detect(struct work_struct *work)
+static irqreturn_t omap_hsmmc_detect(int irq, void *dev_id)
 {
-	struct omap_hsmmc_host *host =
-		container_of(work, struct omap_hsmmc_host, mmc_carddetect_work);
+	struct omap_hsmmc_host *host = dev_id;
 	struct omap_mmc_slot_data *slot = &mmc_slot(host);
 	int carddetect;
 
 	if (host->suspended)
-		return;
+		return IRQ_HANDLED;
 
 	sysfs_notify(&host->mmc->class_dev.kobj, NULL, "cover_switch");
 
@@ -1304,19 +1301,6 @@ static void omap_hsmmc_detect(struct work_struct *work)
 		mmc_detect_change(host->mmc, (HZ * 200) / 1000);
 	else
 		mmc_detect_change(host->mmc, (HZ * 50) / 1000);
-}
-
-/*
- * ISR for handling card insertion and removal
- */
-static irqreturn_t omap_hsmmc_cd_handler(int irq, void *dev_id)
-{
-	struct omap_hsmmc_host *host = (struct omap_hsmmc_host *)dev_id;
-
-	if (host->suspended)
-		return IRQ_HANDLED;
-	schedule_work(&host->mmc_carddetect_work);
-
 	return IRQ_HANDLED;
 }
 
@@ -1918,7 +1902,6 @@ static int __init omap_hsmmc_probe(struct platform_device *pdev)
 	host->next_data.cookie = 1;
 
 	platform_set_drvdata(pdev, host);
-	INIT_WORK(&host->mmc_carddetect_work, omap_hsmmc_detect);
 
 	mmc->ops	= &omap_hsmmc_ops;
 
@@ -2046,10 +2029,11 @@ static int __init omap_hsmmc_probe(struct platform_device *pdev)
 
 	/* Request IRQ for card detect */
 	if ((mmc_slot(host).card_detect_irq)) {
-		ret = request_irq(mmc_slot(host).card_detect_irq,
-				  omap_hsmmc_cd_handler,
-				  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
-				  mmc_hostname(mmc), host);
+		ret = request_threaded_irq(mmc_slot(host).card_detect_irq,
+					   NULL,
+					   omap_hsmmc_detect,
+					   IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+					   mmc_hostname(mmc), host);
 		if (ret) {
 			dev_dbg(mmc_dev(host->mmc),
 				"Unable to grab MMC CD IRQ\n");
@@ -2128,7 +2112,6 @@ static int omap_hsmmc_remove(struct platform_device *pdev)
 		free_irq(host->irq, host);
 		if (mmc_slot(host).card_detect_irq)
 			free_irq(mmc_slot(host).card_detect_irq, host);
-		flush_work_sync(&host->mmc_carddetect_work);
 
 		pm_runtime_put_sync(host->dev);
 		pm_runtime_disable(host->dev);
@@ -2175,7 +2158,6 @@ static int omap_hsmmc_suspend(struct device *dev)
 				return ret;
 			}
 		}
-		cancel_work_sync(&host->mmc_carddetect_work);
 		ret = mmc_suspend_host(host->mmc);
 
 		if (ret == 0) {