diff mbox series

of/platform: increase refcount of fwnode

Message ID 20230812122411.3410399-1-peng.fan@oss.nxp.com
State New
Headers
Series of/platform: increase refcount of fwnode |

Commit Message

Peng Fan (OSS) Aug. 12, 2023, 12:24 p.m. UTC 
  From: Peng Fan <peng.fan@nxp.com>

commit 0f8e5651095b
("of/platform: Propagate firmware node by calling device_set_node()")
use of_fwnode_handle to replace of_node_get, which introduces a side
effect that the refcount is not increased. Then the out of tree
jailhouse hypervisor enable/disable test will trigger kernel dump in
of_overlay_remove, with the following sequence
"
   of_changeset_revert(&overlay_changeset);
   of_changeset_destroy(&overlay_changeset);
   of_overlay_remove(&overlay_id);
"

So increase the refcount to avoid issues.

Fixes: 0f8e5651095b ("of/platform: Propagate firmware node by calling device_set_node()")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/of/platform.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Peng Fan Aug. 17, 2023, 1:18 a.m. UTC | #1 
Hi Andy

> Subject: Re: [PATCH] of/platform: increase refcount of fwnode
> 
> On Sat, Aug 12, 2023 at 08:24:11PM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@nxp.com>
> >
> > commit 0f8e5651095b
> > ("of/platform: Propagate firmware node by calling device_set_node()")
> > use of_fwnode_handle to replace of_node_get, which introduces a side
> > effect that the refcount is not increased. Then the out of tree
> > jailhouse hypervisor enable/disable test will trigger kernel dump in
> > of_overlay_remove, with the following sequence "
> >    of_changeset_revert(&overlay_changeset);
> >    of_changeset_destroy(&overlay_changeset);
> >    of_overlay_remove(&overlay_id);
> > "
> >
> > So increase the refcount to avoid issues.
> 
> Right, thank you for the report!
> I was too busy to send myself a fix (I realized about the issue).
> But what I think about this the actual platform code has to be balanced with
> this. I dunno why we have OF code do one part and the platform core do
> the other. 

No idea, Rob may comment.

It's not obvious and prone to mistakes (like I made).
> 
> Let me look to this closer.

It is 6.5-rc6 now, I hope we could land a fix. If you have better fix, that
would be great.

Thanks,
Peng.

> 
> --
> With Best Regards,
> Andy Shevchenko
>
diff mbox series

Patch

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 0c3475e7d2ff..4659ff5a79c8 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -113,6 +113,7 @@  struct platform_device *of_device_alloc(struct device_node *np,
 				  const char *bus_id,
 				  struct device *parent)
 {
+	struct fwnode_handle *fwnode = of_fwnode_handle(np);
 	struct platform_device *dev;
 	int rc, i, num_reg = 0;
 	struct resource *res;
@@ -141,7 +142,7 @@  struct platform_device *of_device_alloc(struct device_node *np,
 	}
 
 	/* setup generic device info */
-	device_set_node(&dev->dev, of_fwnode_handle(np));
+	device_set_node(&dev->dev, fwnode_handle_get(fwnode));
 	dev->dev.parent = parent ? : &platform_bus;
 
 	if (bus_id)
@@ -221,6 +222,7 @@  static struct amba_device *of_amba_device_create(struct device_node *node,
 						 void *platform_data,
 						 struct device *parent)
 {
+	struct fwnode_handle *fwnode = of_fwnode_handle(node);
 	struct amba_device *dev;
 	int ret;
 
@@ -239,7 +241,7 @@  static struct amba_device *of_amba_device_create(struct device_node *node,
 	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
 
 	/* setup generic device info */
-	device_set_node(&dev->dev, of_fwnode_handle(node));
+	device_set_node(&dev->dev, fwnode_handle_get(fwnode));
 	dev->dev.parent = parent ? : &platform_bus;
 	dev->dev.platform_data = platform_data;
 	if (bus_id)