[PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[Kartik Rajput]

When a device is matched via PRP0001, the driver's OF (DT) match table
must be used to obtain the device match data. If a driver provides both
an acpi_match_table and an of_match_table, the current
acpi_device_get_match_data() path consults the driver's acpi_match_table
and returns NULL (no ACPI ID matches).

Explicitly detect PRP0001 and fetch match data from the driver's
of_match_table via acpi_of_device_get_match_data().

Fixes: 886ca88be6b3 ("ACPI / bus: Respect PRP0001 when retrieving device match data")
Cc: stable@vger.kernel.org
Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
---
Changes in v2:
	* Fix build errors.
---
 drivers/acpi/bus.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 5e110badac7b..6658c4339656 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1031,8 +1031,9 @@ const void *acpi_device_get_match_data(const struct device *dev)
 {
 	const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
 	const struct acpi_device_id *match;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 
-	if (!acpi_ids)
+	if (!strcmp(ACPI_DT_NAMESPACE_HID, acpi_device_hid(adev)))
 		return acpi_of_device_get_match_data(dev);
 
 	match = acpi_match_device(acpi_ids, dev);
-- 
2.43.0

Re: [PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[Sakari Ailus]

Hi Kartik,

On Wed, Jan 07, 2026 at 05:33:18PM +0530, Kartik Rajput wrote:
> When a device is matched via PRP0001, the driver's OF (DT) match table
> must be used to obtain the device match data. If a driver provides both
> an acpi_match_table and an of_match_table, the current
> acpi_device_get_match_data() path consults the driver's acpi_match_table
> and returns NULL (no ACPI ID matches).
> 
> Explicitly detect PRP0001 and fetch match data from the driver's
> of_match_table via acpi_of_device_get_match_data().
> 
> Fixes: 886ca88be6b3 ("ACPI / bus: Respect PRP0001 when retrieving device match data")
> Cc: stable@vger.kernel.org
> Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
> ---
> Changes in v2:
> 	* Fix build errors.

Thanks for the update.

> ---
>  drivers/acpi/bus.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 5e110badac7b..6658c4339656 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -1031,8 +1031,9 @@ const void *acpi_device_get_match_data(const struct device *dev)
>  {
>  	const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
>  	const struct acpi_device_id *match;
> +	struct acpi_device *adev = ACPI_COMPANION(dev);
>  
> -	if (!acpi_ids)
> +	if (!strcmp(ACPI_DT_NAMESPACE_HID, acpi_device_hid(adev)))

I'd swap the arguments to have the static one on the right, i.e.

	if (!strcmp(acpi_device_hid(adev), ACPI_DT_NAMESPACE_HID))

The patch looks good apart from that IMO.

>  		return acpi_of_device_get_match_data(dev);
>  
>  	match = acpi_match_device(acpi_ids, dev);

-- 
Kind regards,

Sakari Ailus

Re: [PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[Kartik Rajput]

On 07/01/26 18:08, Sakari Ailus wrote:
> External email: Use caution opening links or attachments
> 
> 
> Hi Kartik,
> 
> On Wed, Jan 07, 2026 at 05:33:18PM +0530, Kartik Rajput wrote:
>> When a device is matched via PRP0001, the driver's OF (DT) match table
>> must be used to obtain the device match data. If a driver provides both
>> an acpi_match_table and an of_match_table, the current
>> acpi_device_get_match_data() path consults the driver's acpi_match_table
>> and returns NULL (no ACPI ID matches).
>>
>> Explicitly detect PRP0001 and fetch match data from the driver's
>> of_match_table via acpi_of_device_get_match_data().
>>
>> Fixes: 886ca88be6b3 ("ACPI / bus: Respect PRP0001 when retrieving device match data")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
>> ---
>> Changes in v2:
>>        * Fix build errors.
> 
> Thanks for the update.
> 
>> ---
>>   drivers/acpi/bus.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
>> index 5e110badac7b..6658c4339656 100644
>> --- a/drivers/acpi/bus.c
>> +++ b/drivers/acpi/bus.c
>> @@ -1031,8 +1031,9 @@ const void *acpi_device_get_match_data(const struct device *dev)
>>   {
>>        const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
>>        const struct acpi_device_id *match;
>> +     struct acpi_device *adev = ACPI_COMPANION(dev);
>>
>> -     if (!acpi_ids)
>> +     if (!strcmp(ACPI_DT_NAMESPACE_HID, acpi_device_hid(adev)))
> 
> I'd swap the arguments to have the static one on the right, i.e.
> 
>          if (!strcmp(acpi_device_hid(adev), ACPI_DT_NAMESPACE_HID))
> 
> The patch looks good apart from that IMO.
> 
>>                return acpi_of_device_get_match_data(dev);
>>
>>        match = acpi_match_device(acpi_ids, dev);
> 
> --
> Kind regards,
> 
> Sakari Ailus

Hi Sakari,

Thanks for reviewing the patch!

I will make this change in the next version of this patch.

Thanks,
Kartik

Re: [PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[Rafael J. Wysocki]

On Wed, Jan 7, 2026 at 1:03 PM Kartik Rajput <kkartik@nvidia.com> wrote:
>
> When a device is matched via PRP0001, the driver's OF (DT) match table
> must be used to obtain the device match data. If a driver provides both
> an acpi_match_table and an of_match_table, the current
> acpi_device_get_match_data() path consults the driver's acpi_match_table
> and returns NULL (no ACPI ID matches).
>
> Explicitly detect PRP0001 and fetch match data from the driver's
> of_match_table via acpi_of_device_get_match_data().
>
> Fixes: 886ca88be6b3 ("ACPI / bus: Respect PRP0001 when retrieving device match data")
> Cc: stable@vger.kernel.org
> Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
> ---
> Changes in v2:
>         * Fix build errors.
> ---
>  drivers/acpi/bus.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 5e110badac7b..6658c4339656 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -1031,8 +1031,9 @@ const void *acpi_device_get_match_data(const struct device *dev)
>  {
>         const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
>         const struct acpi_device_id *match;
> +       struct acpi_device *adev = ACPI_COMPANION(dev);
>
> -       if (!acpi_ids)

You still need to check acpi_ids against NULL or (better) check adev
against NULL.

> +       if (!strcmp(ACPI_DT_NAMESPACE_HID, acpi_device_hid(adev)))
>                 return acpi_of_device_get_match_data(dev);
>
>         match = acpi_match_device(acpi_ids, dev);
> --

Re: [PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[Kartik Rajput]

On 07/01/26 18:24, Rafael J. Wysocki wrote:
> External email: Use caution opening links or attachments
> 
> 
> On Wed, Jan 7, 2026 at 1:03 PM Kartik Rajput <kkartik@nvidia.com> wrote:
>>
>> When a device is matched via PRP0001, the driver's OF (DT) match table
>> must be used to obtain the device match data. If a driver provides both
>> an acpi_match_table and an of_match_table, the current
>> acpi_device_get_match_data() path consults the driver's acpi_match_table
>> and returns NULL (no ACPI ID matches).
>>
>> Explicitly detect PRP0001 and fetch match data from the driver's
>> of_match_table via acpi_of_device_get_match_data().
>>
>> Fixes: 886ca88be6b3 ("ACPI / bus: Respect PRP0001 when retrieving device match data")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
>> ---
>> Changes in v2:
>>          * Fix build errors.
>> ---
>>   drivers/acpi/bus.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
>> index 5e110badac7b..6658c4339656 100644
>> --- a/drivers/acpi/bus.c
>> +++ b/drivers/acpi/bus.c
>> @@ -1031,8 +1031,9 @@ const void *acpi_device_get_match_data(const struct device *dev)
>>   {
>>          const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
>>          const struct acpi_device_id *match;
>> +       struct acpi_device *adev = ACPI_COMPANION(dev);
>>
>> -       if (!acpi_ids)
> 
> You still need to check acpi_ids against NULL or (better) check adev
> against NULL.
> 

Hi Rafael,

Thanks for reviewing the patch.

Yes, it looks like adev should be NULL-checked. acpi_of_device_get_match_data()
also uses the adev reference and passes it to acpi_of_match_device(), which checks
it against NULL.

I will make this change in the next revision.

Thanks,
Kartik

Re: [PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[Andy Shevchenko]

On Wed, Jan 07, 2026 at 05:33:18PM +0530, Kartik Rajput wrote:
> When a device is matched via PRP0001, the driver's OF (DT) match table
> must be used to obtain the device match data. If a driver provides both
> an acpi_match_table and an of_match_table, the current
> acpi_device_get_match_data() path consults the driver's acpi_match_table
> and returns NULL (no ACPI ID matches).

Since we have both tables, why the actual ACPI HID of the device in question
(actually which one?) can't be used?

> Explicitly detect PRP0001 and fetch match data from the driver's
> of_match_table via acpi_of_device_get_match_data().

In principle we can go this way, but can you tell a bit more of a story?
Why the device in question can't use existed or a newly allocated ACPI HID for
that?

...

> @@ -1031,8 +1031,9 @@ const void *acpi_device_get_match_data(const struct device *dev)
>  {
>  	const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
>  	const struct acpi_device_id *match;
> +	struct acpi_device *adev = ACPI_COMPANION(dev);

Please, keep it in reversed xmas tree order.

> -	if (!acpi_ids)
> +	if (!strcmp(ACPI_DT_NAMESPACE_HID, acpi_device_hid(adev)))


>  		return acpi_of_device_get_match_data(dev);
>  
>  	match = acpi_match_device(acpi_ids, dev);

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[Kartik Rajput]

Hi Andy,

Thanks for reviewing the patch!

On 07/01/26 21:17, Andy Shevchenko wrote:
> External email: Use caution opening links or attachments
> 
> 
> On Wed, Jan 07, 2026 at 05:33:18PM +0530, Kartik Rajput wrote:
>> When a device is matched via PRP0001, the driver's OF (DT) match table
>> must be used to obtain the device match data. If a driver provides both
>> an acpi_match_table and an of_match_table, the current
>> acpi_device_get_match_data() path consults the driver's acpi_match_table
>> and returns NULL (no ACPI ID matches).
> 
> Since we have both tables, why the actual ACPI HID of the device in question
> (actually which one?) can't be used?
> 
>> Explicitly detect PRP0001 and fetch match data from the driver's
>> of_match_table via acpi_of_device_get_match_data().
> 
> In principle we can go this way, but can you tell a bit more of a story?
> Why the device in question can't use existed or a newly allocated ACPI HID for
> that?
> 

While testing PRP0001-based matching with the Tegra fuse driver on an SoC that does
not yet have an allocated ACPI HID, device_get_match_data() returned NULL because
the driver also provides an acpi_match_table.

Commit 886ca88be6b3 ("ACPI / bus: Respect PRP0001 when retrieving device match data")
was intended to address this by honoring PRP0001 when retrieving match data. However,
when a driver provides an ACPI match table, acpi_device_get_match_data() currently
consults only that table, resulting in NULL match data despite a successful
PRP0001 match.

> ...
> 
>> @@ -1031,8 +1031,9 @@ const void *acpi_device_get_match_data(const struct device *dev)
>>   {
>>        const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
>>        const struct acpi_device_id *match;
>> +     struct acpi_device *adev = ACPI_COMPANION(dev);
> 
> Please, keep it in reversed xmas tree order.
> 

Ack. I will update this in the next revision.

Thanks,
Kartik

Re: [PATCH v2] ACPI: bus: Use OF match data for PRP0001 matched devices

[Andy Shevchenko]

On Thu, Jan 08, 2026 at 05:57:35PM +0530, Kartik Rajput wrote:
> On 07/01/26 21:17, Andy Shevchenko wrote:
> > On Wed, Jan 07, 2026 at 05:33:18PM +0530, Kartik Rajput wrote:

> > > When a device is matched via PRP0001, the driver's OF (DT) match table
> > > must be used to obtain the device match data. If a driver provides both
> > > an acpi_match_table and an of_match_table, the current
> > > acpi_device_get_match_data() path consults the driver's acpi_match_table
> > > and returns NULL (no ACPI ID matches).
> > 
> > Since we have both tables, why the actual ACPI HID of the device in question
> > (actually which one?) can't be used?
> > 
> > > Explicitly detect PRP0001 and fetch match data from the driver's
> > > of_match_table via acpi_of_device_get_match_data().
> > 
> > In principle we can go this way, but can you tell a bit more of a story?
> > Why the device in question can't use existed or a newly allocated ACPI HID for
> > that?
> 
> While testing PRP0001-based matching with the Tegra fuse driver on an SoC that does
> not yet have an allocated ACPI HID,

Which means in the production you do not need this patch. Allocate ID and go with it.

> device_get_match_data() returned NULL because
> the driver also provides an acpi_match_table.
> 
> Commit 886ca88be6b3 ("ACPI / bus: Respect PRP0001 when retrieving device match data")
> was intended to address this by honoring PRP0001 when retrieving match data. However,
> when a driver provides an ACPI match table, acpi_device_get_match_data() currently
> consults only that table, resulting in NULL match data despite a successful
> PRP0001 match.

Which is expected behaviour. So there are two cases I can see that might make
this patch valid:

1) the preproduction development when the driver has both tables and formal
ACPI HID is not allocated yet (this what has to be the main "why" point
in the commit message);

2) a driver that got ACPI HID from somebody else and breaks the PRP0001 setups
for others (no evidences so far, but I admit there is a potential to have a
such).

That said, having the Fixes tag is unrequired.

-- 
With Best Regards,
Andy Shevchenko