Patch "drivercore: Fix unregistration path of platform devices" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

drivercore: Fix unregistration path of platform devices

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
drivercore-fix-unregistration-path-of-platform-devices.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Grant Likely <[email protected]>
Date: Sun, 7 Jun 2015 15:20:11 +0100
Subject: drivercore: Fix unregistration path of platform devices

From: Grant Likely <[email protected]>

commit 7f5dcaf1fdf289767a126a0a5cc3ef39b5254b06 upstream.

The unregister path of platform_device is broken. On registration, it will register all resources with either a parent already set, or type==IORESOURCE_{IO,MEM}. However, on unregister it will release everything with type==IORESOURCE_{IO,MEM}, but ignore the others. There are also cases where resources don't get registered in the first place, like with devices created by of_platform_populate()*.

Fix the unregister path to be symmetrical with the register path by checking the parent pointer instead of the type field to decide which resources to unregister. This is safe because the upshot of the registration path algorithm is that registered resources have a parent pointer, and non-registered resources do not.

* It can be argued that of_platform_populate() should be registering it's resources, and they argument has some merit. However, there are quite a few platforms that end up broken if we try to do that due to overlapping resources in the device tree. Until that is fixed, we need to solve the immediate problem.

---
 drivers/base/platform.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

@@ -375,9 +375,7 @@ int platform_device_add(struct platform_
 
 	while (--i >= 0) {
 		struct resource *r = &pdev->resource[i];
-		unsigned long type = resource_type(r);
-
-		if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
+		if (r->parent)
 			release_resource(r);
 	}
 

@@ -408,9 +406,7 @@ void platform_device_del(struct platform
 
 		for (i = 0; i < pdev->num_resources; i++) {
 			struct resource *r = &pdev->resource[i];
-			unsigned long type = resource_type(r);
-
-			if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
+			if (r->parent)
 				release_resource(r);
 		}
 	}

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/drivercore-fix-unregistration-path-of-platform-devices.patch