FAILED: patch "[PATCH] [media] exynos4-is: Clear isp-i2c adapter" failed to apply to 4.8-stable tree

The patch below does not apply to the 4.8-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Sylwester Nawrocki <[email protected]>
Date: Tue, 13 Sep 2016 11:39:33 -0300
Subject: [PATCH] [media] exynos4-is: Clear isp-i2c adapter
power.ignore_children flag

Since commit 04f59143b571161d25315dd52d7a2ecc022cb71a ("i2c: let I2C masters ignore their children for PM") the power.ignore_children flag is set when registering an I2C adapter. Since I2C transfers are not managed by the fimc-isp-i2c driver its clients use pm_runtime_* calls directly to communicate required power state of the bus controller.

However, when the power.ignore_children flag is set that doesn't work, so clear that flag back after registering the adapter. While at it drop pm_runtime_enable() call on the i2c_adapter as it is already done by the I2C subsystem when registering I2C adapter.

This patch is meant as a minimal change to fix the regression, eventually the I2C_ISPx clock handling will be moved to the top level fimc-is driver and whole runtime PM code is going to be dropped from the fimc-is-i2c module.

index fd888ef447a9..6bba4ca022be 100644
@@ -55,23 +55,33 @@ static int fimc_is_i2c_probe(struct platform_device *pdev)
 	i2c_adap->algo = &fimc_is_i2c_algorithm;
 	i2c_adap->class = I2C_CLASS_SPD;
 
-	ret = i2c_add_adapter(i2c_adap);
-	if (ret < 0)
-		return ret;
-
 	platform_set_drvdata(pdev, isp_i2c);
-
 	pm_runtime_enable(&pdev->dev);
-	pm_runtime_enable(&i2c_adap->dev);
 
+	ret = i2c_add_adapter(i2c_adap);
+	if (ret < 0)
+		goto err_pm_dis;
+	/*
+	 * Client drivers of this adapter don't do any I2C transfers as that
+	 * is handled by the ISP firmware.  But we rely on the runtime PM
+	 * state propagation from the clients up to the adapter driver so
+	 * clear the ignore_children flags here.  PM rutnime calls are not
+	 * used in probe() handler of clients of this adapter so there is
+	 * no issues with clearing the flag right after registering the I2C
+	 * adapter.
+	 */
+	pm_suspend_ignore_children(&i2c_adap->dev, false);
 	return 0;
+
+err_pm_dis:
+	pm_runtime_disable(&pdev->dev);
+	return ret;
 }
 
 static int fimc_is_i2c_remove(struct platform_device *pdev)
 {
 	struct fimc_is_i2c *isp_i2c = platform_get_drvdata(pdev);
 
-	pm_runtime_disable(&isp_i2c->adapter.dev);
 	pm_runtime_disable(&pdev->dev);
 	i2c_del_adapter(&isp_i2c->adapter);