linux-kernel - Re: [PATCH v3] ACPI: bus: Use OF match data for PRP0001 matched devices

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Message-ID: <20260109101302.GW2275908@black.igk.intel.com>
Date: Fri, 9 Jan 2026 11:13:02 +0100
From: Mika Westerberg <mika.westerberg@...ux.intel.com>
To: Kartik Rajput <kkartik@...dia.com>
Cc: lenb@...nel.org, sakari.ailus@...ux.intel.com,
	andriy.shevchenko@...ux.intel.com, thierry.reding@...il.com,
	jonathanh@...dia.com, linux-acpi@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] ACPI: bus: Use OF match data for PRP0001 matched
 devices

On Fri, Jan 09, 2026 at 03:23:58PM +0530, Kartik Rajput wrote:
> During pre-production development, drivers may provide both ACPI and OF
> match tables while a formal ACPI HID for the device is not yet
> allocated. Such devices are enumerated via PRP0001. In this case,
> acpi_device_get_match_data() consults only the driver’s ACPI match table
> and returns NULL, even though the device was successfully matched via
> PRP0001.
> 
> This behavior also risks breaking existing PRP0001 setups if a driver
> later gains an ACPI HID, as the presence of an ACPI match table changes
> the match-data lookup path.
> 
> Explicitly detect PRP0001 and fetch match data from the driver's
> OF match table via acpi_of_device_get_match_data().
> 
> Signed-off-by: Kartik Rajput <kkartik@...dia.com>
> ---
> Changes in v3:
>         * Swap arguments while comparing HID against PRP0001.
>         * Check value of adev against NULL.
>         * Declare variables in reversed xmas tree order.
>         * Update commit message.
> Changes in v2:
>         * Fix build errors.
> ---
>  drivers/acpi/bus.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 5e110badac7b..e960df2fcea7 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -1030,9 +1030,13 @@ static const void *acpi_of_device_get_match_data(const struct device *dev)
>  const void *acpi_device_get_match_data(const struct device *dev)
>  {
>  	const struct acpi_device_id *acpi_ids = dev->driver->acpi_match_table;
> +	struct acpi_device *adev = ACPI_COMPANION(dev);
>  	const struct acpi_device_id *match;
>  
> -	if (!acpi_ids)
> +	if (!adev)
> +		return NULL;
> +
> +	if (!strcmp(acpi_device_hid(adev), ACPI_DT_NAMESPACE_HID))
>  		return acpi_of_device_get_match_data(dev);
>  
>  	match = acpi_match_device(acpi_ids, dev);

Should you check with !acpi_ids still here?

> -- 
> 2.43.0