Re: [PATCH v2 3/4] ACPI / scan: Recognize Apple SPI and I2C slaves

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Wed, Jun 28, 2017 at 07:20:19PM +0200, Lukas Wunner wrote:
> SPI and I2C slaves are enumerated by their respective parents rather
> than the ACPI core.  They are recognized by presence of _CRS resources,
> which however are missing on Macs.  Check for presence of device
> properties instead.
> 
> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Federico Lorenzi <florenzi@gmail.com>
> Reported-and-tested-by: Ronald Tschalär <ronald@innovation.ch>
> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> ---
> Changes v1 -> v2:
> - Newly inserted patch in v2 to fix an enumeration issue. (Ronald)
> 
>  drivers/acpi/scan.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index d4ff2cd1f738..c565e74bd2dd 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1444,6 +1444,12 @@ static bool acpi_is_spi_i2c_slave(struct acpi_device *device)
>  	struct list_head resource_list;
>  	bool is_spi_i2c_slave = false;
>  
> +	/* Macs use device properties in lieu of _CRS resources */
> +	if (IS_ENABLED(CONFIG_X86) && dmi_match(DMI_SYS_VENDOR, "Apple Inc.") &&

Do we really need these checks?

> +	    (device_property_present(&device->dev, "spiSclkPeriod") ||
> +	     device_property_present(&device->dev, "i2cAddress")))
> +		return true;
> +
>  	INIT_LIST_HEAD(&resource_list);
>  	acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
>  			       &is_spi_i2c_slave);
> -- 
> 2.11.0