[v3] mfd: core: Preserve OF node when ACPI handle is present

[PATCH v3] mfd: core: Preserve OF node when ACPI handle is present

Posted by Brian Mak 3 weeks, 5 days ago

Switch device_set_node to set_primary_fwnode, so that the ACPI fwnode
does not overwrite the of_node with NULL.

This allows MFD children with both OF nodes and ACPI handles to have OF
nodes again.

Fixes: 51e3b257099d ("mfd: core: Make use of device_set_node()")
Cc: stable@vger.kernel.org
Signed-off-by: Brian Mak <makb@juniper.net>
---

v3: Changed FIXME to NOTE, as this will not be addressed in the near
future.

v2: Use open-coded logic for clarity and add FIXME.

 drivers/mfd/mfd-core.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index 6be58eb5a746..e862448b93b3 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -88,7 +88,20 @@ static void mfd_acpi_add_device(const struct mfd_cell *cell,
 		}
 	}
 
-	device_set_node(&pdev->dev, acpi_fwnode_handle(adev ?: parent));
+	/*
+	 * NOTE: The fwnode design doesn't allow proper stacking/sharing. This
+	 * should eventually turn into a device fwnode API call that will allow
+	 * prepending to a list of fwnodes (with ACPI taking precedence).
+	 *
+	 * set_primary_fwnode() is used here, instead of device_set_node(), as
+	 * device_set_node() will overwrite the existing fwnode, which may be an
+	 * OF node that was populated earlier. To support a use case where ACPI
+	 * and OF is used in conjunction, we call set_primary_fwnode() instead.
+	 */
+	if (adev)
+		set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(adev));
+	else
+		set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(parent));
 }
 #else
 static inline void mfd_acpi_add_device(const struct mfd_cell *cell,

base-commit: d9d32e5bd5a4e57675f2b70ddf73c3dc5cf44fc2
-- 
2.25.1

Re: [PATCH v3] mfd: core: Preserve OF node when ACPI handle is present

Posted by Lee Jones 2 weeks, 5 days ago

On Wed, 11 Mar 2026, Brian Mak wrote:

> Switch device_set_node to set_primary_fwnode, so that the ACPI fwnode
> does not overwrite the of_node with NULL.
> 
> This allows MFD children with both OF nodes and ACPI handles to have OF
> nodes again.
> 
> Fixes: 51e3b257099d ("mfd: core: Make use of device_set_node()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Brian Mak <makb@juniper.net>
> ---
> 
> v3: Changed FIXME to NOTE, as this will not be addressed in the near
> future.
> 
> v2: Use open-coded logic for clarity and add FIXME.
> 
>  drivers/mfd/mfd-core.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index 6be58eb5a746..e862448b93b3 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
> @@ -88,7 +88,20 @@ static void mfd_acpi_add_device(const struct mfd_cell *cell,
>  		}
>  	}
>  
> -	device_set_node(&pdev->dev, acpi_fwnode_handle(adev ?: parent));
> +	/*
> +	 * NOTE: The fwnode design doesn't allow proper stacking/sharing. This
> +	 * should eventually turn into a device fwnode API call that will allow
> +	 * prepending to a list of fwnodes (with ACPI taking precedence).
> +	 *
> +	 * set_primary_fwnode() is used here, instead of device_set_node(), as
> +	 * device_set_node() will overwrite the existing fwnode, which may be an
> +	 * OF node that was populated earlier. To support a use case where ACPI
> +	 * and OF is used in conjunction, we call set_primary_fwnode() instead.
> +	 */
> +	if (adev)
> +		set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(adev));
> +	else
> +		set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(parent));

Sorry to mess you around again, but how do you feel about:

  set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(adev ?: parent));

>  }
>  #else
>  static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
> 
> base-commit: d9d32e5bd5a4e57675f2b70ddf73c3dc5cf44fc2
> -- 
> 2.25.1
> 

-- 
Lee Jones [李琼斯]

Re: [PATCH v3] mfd: core: Preserve OF node when ACPI handle is present

Posted by Andy Shevchenko 2 weeks, 4 days ago

On Thu, Mar 19, 2026 at 06:12:31PM +0000, Lee Jones wrote:
> On Wed, 11 Mar 2026, Brian Mak wrote:

...

> > +	if (adev)
> > +		set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(adev));
> > +	else
> > +		set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(parent));
> 
> Sorry to mess you around again, but how do you feel about:
> 
>   set_primary_fwnode(&pdev->dev, acpi_fwnode_handle(adev ?: parent));

If you think it's better, no objections from me.

Some maintainers prefer avoiding ternary, and specifically Elvis, some not —
hard to remember everybody's preferences :-)

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v3] mfd: core: Preserve OF node when ACPI handle is present

Posted by Andy Shevchenko 3 weeks, 5 days ago

On Wed, Mar 11, 2026 at 12:02:25PM -0700, Brian Mak wrote:
> Switch device_set_node to set_primary_fwnode, so that the ACPI fwnode
> does not overwrite the of_node with NULL.
> 
> This allows MFD children with both OF nodes and ACPI handles to have OF
> nodes again.

Haven't I given a tag already?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v3] mfd: core: Preserve OF node when ACPI handle is present

Posted by Brian Mak 3 weeks, 5 days ago

On Mar 11, 2026, at 1:25 PM, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Wed, Mar 11, 2026 at 12:02:25PM -0700, Brian Mak wrote:
>> Switch device_set_node to set_primary_fwnode, so that the ACPI fwnode
>> does not overwrite the of_node with NULL.
>> 
>> This allows MFD children with both OF nodes and ACPI handles to have OF
>> nodes again.
> 
> Haven't I given a tag already?

Sorry, yes you did, I forgot to copy it over, my bad:

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Best,
Brian