X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Fhwspinlock%2Fomap_hwspinlock.c;h=c1e2cd4d85fe3f98034bfc70bc9ebd420cdcca30;hb=e1e4528f8c99624494043597859e7f9421832833;hp=292869cc90343fd330ce29e9bcdf3c8575a2b7f7;hpb=b2c6b3e0611c58fbeb6b9c0892b6249f7bdfaf6b;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c
index 292869cc9034..c1e2cd4d85fe 100644
--- a/drivers/hwspinlock/omap_hwspinlock.c
+++ b/drivers/hwspinlock/omap_hwspinlock.c
@@ -98,10 +98,29 @@ static int omap_hwspinlock_probe(struct platform_device *pdev)
 	if (!io_base)
 		return -ENOMEM;
 
+	/*
+	 * make sure the module is enabled and clocked before reading
+	 * the module SYSSTATUS register
+	 */
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&pdev->dev);
+		goto iounmap_base;
+	}
+
 	/* Determine number of locks */
 	i = readl(io_base + SYSSTATUS_OFFSET);
 	i >>= SPINLOCK_NUMLOCKS_BIT_OFFSET;
 
+	/*
+	 * runtime PM will make sure the clock of this module is
+	 * enabled again iff at least one lock is requested
+	 */
+	ret = pm_runtime_put(&pdev->dev);
+	if (ret < 0)
+		goto iounmap_base;
+
 	/* one of the four lsb's must be set, and nothing else */
 	if (hweight_long(i & 0xf) != 1 || i > 8) {
 		ret = -EINVAL;
@@ -121,12 +140,6 @@ static int omap_hwspinlock_probe(struct platform_device *pdev)
 	for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
 		hwlock->priv = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i;
 
-	/*
-	 * runtime PM will make sure the clock of this module is
-	 * enabled iff at least one lock is requested
-	 */
-	pm_runtime_enable(&pdev->dev);
-
 	ret = hwspin_lock_register(bank, &pdev->dev, &omap_hwspinlock_ops,
 						pdata->base_id, num_locks);
 	if (ret)
@@ -135,9 +148,9 @@ static int omap_hwspinlock_probe(struct platform_device *pdev)
 	return 0;
 
 reg_fail:
-	pm_runtime_disable(&pdev->dev);
 	kfree(bank);
 iounmap_base:
+	pm_runtime_disable(&pdev->dev);
 	iounmap(io_base);
 	return ret;
 }