Re: [PATCH v6 3/3] ACPI: delay enumeration of devices with a _DEP pointing to IVSC device

[Hans de Goede <hdegoede@redhat.com>]

Hi Wentong,

On 4/25/23 03:43, Wentong Wu wrote:
> Inside IVSC, switching ownership requires an interface with two
> different hardware modules, ACE and CSI. The software interface
> to these modules is based on Intel MEI framework. Usually mei
> client devices are dynamically created, so the info of consumers
> depending on mei client devices is not present in the firmware
> tables.
> 
> This causes problems with the probe ordering with respect to
> drivers for consumers of these mei client devices. But on these
> camera sensor devices, the ACPI nodes describing the sensors all
> have a _DEP dependency on the matching mei bus ACPI device, so
> adding IVSC mei bus ACPI device to acpi_honor_dep_ids allows
> solving the probe-ordering problem by delaying the enumeration of
> ACPI-devices which have a _DEP dependency on an IVSC mei bus ACPI
> device.
> 
> On TGL platform, the HID of IVSC mei bus ACPI device is INTC1059,
> and on ADL platform, the HID is INTC1095. So add both of them to
> acpi_honor_dep_ids.
> 
> Signed-off-by: Wentong Wu <wentong.wu@intel.com>
> ---
>  drivers/acpi/scan.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 2743444..89368d7 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -796,6 +796,8 @@ static const char * const acpi_ignore_dep_ids[] = {
>  /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
>  static const char * const acpi_honor_dep_ids[] = {
>  	"INT3472", /* Camera sensor PMIC / clk and regulator info */
> +	"INTC1059",
> +	"INTC1095",

Can you please add a short comment after these to explain what they are for,
e.g.:

	"INTC1059", /* IVSC (TGL) driver must be loaded to allow i2c access to camera sensors */
	"INTC1095", /* IVSC (ADL) driver must be loaded to allow i2c access to camera sensors */

>  	NULL
>  };
>  

Regards,

Hans