[PATCH v1] ACPI: bus: Fix MFD child automatic modprobe issue

[PATCH v1] ACPI: bus: Fix MFD child automatic modprobe issue

[Pratap Nirujogi]

MFD child devices sharing parent's ACPI Companion fails to probe as
acpi_companion_match() returns incompatible ACPI Companion handle for
binding with the check for pnp.type.backlight added recently. Remove this
pnp.type.backlight check in acpi_companion_match() to fix the automatic
modprobe issue.

Fixes: 7a7a7ed5f8bdb ("ACPI: scan: Register platform devices for backlight device objects")
Signed-off-by: Pratap Nirujogi <pratap.nirujogi@amd.com>
---
 drivers/acpi/bus.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index f6707325f5821..2ec095e2009e4 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -818,9 +818,6 @@ const struct acpi_device *acpi_companion_match(const struct device *dev)
 	if (list_empty(&adev->pnp.ids))
 		return NULL;
 
-	if (adev->pnp.type.backlight)
-		return adev;
-
 	return acpi_primary_dev_companion(adev, dev);
 }
 
-- 
2.43.0

Re: [PATCH v1] ACPI: bus: Fix MFD child automatic modprobe issue

[Rafael J. Wysocki]

On Wed, Mar 18, 2026 at 4:49 AM Pratap Nirujogi <pratap.nirujogi@amd.com> wrote:
>
> MFD child devices sharing parent's ACPI Companion fails to probe as
> acpi_companion_match() returns incompatible ACPI Companion handle for
> binding with the check for pnp.type.backlight added recently. Remove this
> pnp.type.backlight check in acpi_companion_match() to fix the automatic
> modprobe issue.
>
> Fixes: 7a7a7ed5f8bdb ("ACPI: scan: Register platform devices for backlight device objects")
> Signed-off-by: Pratap Nirujogi <pratap.nirujogi@amd.com>
> ---
>  drivers/acpi/bus.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index f6707325f5821..2ec095e2009e4 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -818,9 +818,6 @@ const struct acpi_device *acpi_companion_match(const struct device *dev)
>         if (list_empty(&adev->pnp.ids))
>                 return NULL;
>
> -       if (adev->pnp.type.backlight)
> -               return adev;
> -

Good catch!

I forgot to remove this in

https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?h=acpi-7.0-rc4&id=6ab3532b4c98f4e51969f0e5f3fc919c535f3ce1

>         return acpi_primary_dev_companion(adev, dev);
>  }
>
> --

So applied as 7.0-rc material, thanks!

Re: [PATCH v1] ACPI: bus: Fix MFD child automatic modprobe issue

[Nirujogi, Pratap]

On 3/18/2026 7:02 AM, Rafael J. Wysocki wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> On Wed, Mar 18, 2026 at 4:49 AM Pratap Nirujogi <pratap.nirujogi@amd.com> wrote:
>>
>> MFD child devices sharing parent's ACPI Companion fails to probe as
>> acpi_companion_match() returns incompatible ACPI Companion handle for
>> binding with the check for pnp.type.backlight added recently. Remove this
>> pnp.type.backlight check in acpi_companion_match() to fix the automatic
>> modprobe issue.
>>
>> Fixes: 7a7a7ed5f8bdb ("ACPI: scan: Register platform devices for backlight device objects")
>> Signed-off-by: Pratap Nirujogi <pratap.nirujogi@amd.com>
>> ---
>>   drivers/acpi/bus.c | 3 ---
>>   1 file changed, 3 deletions(-)
>>
>> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
>> index f6707325f5821..2ec095e2009e4 100644
>> --- a/drivers/acpi/bus.c
>> +++ b/drivers/acpi/bus.c
>> @@ -818,9 +818,6 @@ const struct acpi_device *acpi_companion_match(const struct device *dev)
>>          if (list_empty(&adev->pnp.ids))
>>                  return NULL;
>>
>> -       if (adev->pnp.type.backlight)
>> -               return adev;
>> -
> 
> Good catch!
> 
> I forgot to remove this in
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?h=acpi-7.0-rc4&id=6ab3532b4c98f4e51969f0e5f3fc919c535f3ce1
> 
>>          return acpi_primary_dev_companion(adev, dev);
>>   }
>>
>> --
> 
> So applied as 7.0-rc material, thanks!

Thanks, Rafael.