Le 24/12/2025 à 11:52, Haoxiang Li a écrit :

On Wed, 24 Dec 2025 10:57:52 +0100, Christophe Leroy wrote:

quoted

Ok, then this needs to be said in the commit message.

I will add it in the patch v2.

quoted

By the way I'm a bit puzzled by the device_add() doc versus the
put_device(), because it looks like device_add() already calls
put_device() in its error path, see
https://elixir.bootlin.com/linux/v6.19-rc2/source/drivers/base/core.c#L3716

I think this is because device_add() increment the reference in the
beginning, see
https://elixir.bootlin.com/linux/v6.19-rc2/source/drivers/base/core.c#L3580
and if device_add() fails, another put_device() should be called to decrement
the reference which is obtained by device_initialize().

Ah yes, I see.

But then all exit paths in fsl_mc_device_add() after device_initialize() 
should call put_device() ?

Then in fact the fix should instead be the following, shouldn't it ?

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c 

b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 25845c04e562..6d132144ce25 100644

--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c

@@ -905,11 +905,7 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,
  	return 0;

  error_cleanup_dev:
-	kfree(mc_dev->regions);
-	if (mc_bus)
-		kfree(mc_bus);
-	else
-		kfree(mc_dev);
+	put_device(&mc_dev->dev);

  	return error;
  }