Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

3 files changed, 32 insertions, 9 deletions

diff --git a/kernel/drivers/char/hw_random/core.c b/kernel/drivers/char/hw_random/core.c
index 6f497aa1b..cf2502057 100644
--- a/kernel/drivers/char/hw_random/core.c
+++ b/kernel/drivers/char/hw_random/core.c
@@ -84,14 +84,14 @@ static size_t rng_buffer_size(void)
 
 static void add_early_randomness(struct hwrng *rng)
 {
-	unsigned char bytes[16];
 	int bytes_read;
+	size_t size = min_t(size_t, 16, rng_buffer_size());
 
 	mutex_lock(&reading_mutex);
-	bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1);
+	bytes_read = rng_get_data(rng, rng_buffer, size, 1);
 	mutex_unlock(&reading_mutex);
 	if (bytes_read > 0)
-		add_device_randomness(bytes, bytes_read);
+		add_device_randomness(rng_buffer, bytes_read);
 }
 
 static inline void cleanup_rng(struct kref *kref)
diff --git a/kernel/drivers/char/hw_random/exynos-rng.c b/kernel/drivers/char/hw_random/exynos-rng.c
index 30cf46231..7845a38b6 100644
--- a/kernel/drivers/char/hw_random/exynos-rng.c
+++ b/kernel/drivers/char/hw_random/exynos-rng.c
@@ -89,6 +89,7 @@ static int exynos_read(struct hwrng *rng, void *buf,
 						struct exynos_rng, rng);
 	u32 *data = buf;
 	int retry = 100;
+	int ret = 4;
 
 	pm_runtime_get_sync(exynos_rng->dev);
 
@@ -97,23 +98,27 @@ static int exynos_read(struct hwrng *rng, void *buf,
 	while (!(exynos_rng_readl(exynos_rng,
 			EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE) && --retry)
 		cpu_relax();
-	if (!retry)
-		return -ETIMEDOUT;
+	if (!retry) {
+		ret = -ETIMEDOUT;
+		goto out;
+	}
 
 	exynos_rng_writel(exynos_rng, PRNG_DONE, EXYNOS_PRNG_STATUS_OFFSET);
 
 	*data = exynos_rng_readl(exynos_rng, EXYNOS_PRNG_OUT1_OFFSET);
 
+out:
 	pm_runtime_mark_last_busy(exynos_rng->dev);
 	pm_runtime_put_sync_autosuspend(exynos_rng->dev);
 
-	return 4;
+	return ret;
 }
 
 static int exynos_rng_probe(struct platform_device *pdev)
 {
 	struct exynos_rng *exynos_rng;
 	struct resource *res;
+	int ret;
 
 	exynos_rng = devm_kzalloc(&pdev->dev, sizeof(struct exynos_rng),
 					GFP_KERNEL);
@@ -141,7 +146,13 @@ static int exynos_rng_probe(struct platform_device *pdev)
 	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
-	return devm_hwrng_register(&pdev->dev, &exynos_rng->rng);
+	ret = devm_hwrng_register(&pdev->dev, &exynos_rng->rng);
+	if (ret) {
+		pm_runtime_dont_use_autosuspend(&pdev->dev);
+		pm_runtime_disable(&pdev->dev);
+	}
+
+	return ret;
 }
 
 #ifdef CONFIG_PM
diff --git a/kernel/drivers/char/hw_random/omap-rng.c b/kernel/drivers/char/hw_random/omap-rng.c
index 8a1432e8b..f5c26a5f6 100644
--- a/kernel/drivers/char/hw_random/omap-rng.c
+++ b/kernel/drivers/char/hw_random/omap-rng.c
@@ -384,7 +384,12 @@ static int omap_rng_probe(struct platform_device *pdev)
 	}
 
 	pm_runtime_enable(&pdev->dev);
-	pm_runtime_get_sync(&pdev->dev);
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to runtime_get device: %d\n", ret);
+		pm_runtime_put_noidle(&pdev->dev);
+		goto err_ioremap;
+	}
 
 	ret = (dev->of_node) ? of_get_omap_rng_device_details(priv, pdev) :
 				get_omap_rng_device_details(priv);
@@ -435,8 +440,15 @@ static int __maybe_unused omap_rng_suspend(struct device *dev)
 static int __maybe_unused omap_rng_resume(struct device *dev)
 {
 	struct omap_rng_dev *priv = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		dev_err(dev, "Failed to runtime_get device: %d\n", ret);
+		pm_runtime_put_noidle(dev);
+		return ret;
+	}
 
-	pm_runtime_get_sync(dev);
 	priv->pdata->init(priv);
 
 	return 0;