Re: [PATCH] ACPI: video: Don't allow MFD devices to probe

["Nirujogi, Pratap" <pnirujog@amd.com>]

This patch resolves the regression issue observed with AMD ISP device in 
kernel version 7.0-rc2.

Tested-by: Pratap Nirujogi <pratap.nirujogi@amd.com>

Thanks,
Pratap

On 3/5/2026 9:51 PM, Mario Limonciello (AMD) wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> After ACPI video was converted into a platform device in
> commit 02c057ddefef5 ("ACPI: video: Convert the driver to a platform one")
> other devices that are MFD children of LNXVIDEO are being probed.
> This isn't intended.
> 
> During probe detect MFD cells and reject them.
> 
> Fixes: 02c057ddefef5 ("ACPI: video: Convert the driver to a platform one")
> Reported-by: Pratap Nirujogi <pnirujog@amd.com>
> Closes: https://lore.kernel.org/regressions/007e3390-6b2b-457e-83c7-c794c5952018@amd.com/
> Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
> ---
>   drivers/acpi/acpi_video.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c
> index 3fa28f1abca38..2cb526775ac47 100644
> --- a/drivers/acpi/acpi_video.c
> +++ b/drivers/acpi/acpi_video.c
> @@ -14,6 +14,7 @@
>   #include <linux/init.h>
>   #include <linux/types.h>
>   #include <linux/list.h>
> +#include <linux/mfd/core.h>
>   #include <linux/mutex.h>
>   #include <linux/input.h>
>   #include <linux/backlight.h>
> @@ -1988,6 +1989,9 @@ static int acpi_video_bus_probe(struct platform_device *pdev)
>          int error;
>          acpi_status status;
> 
> +       if (mfd_get_cell(pdev))
> +               return -ENODEV;
> +
>          status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
>                                  acpi_dev_parent(device)->handle, 1,
>                                  acpi_video_bus_match, NULL,
> --
> 2.43.0
>