On Thu, Jun 29, 2017 at 10:46:04AM +0200, Lukas Wunner wrote:

On Thu, Jun 29, 2017 at 10:34:20AM +0300, Mika Westerberg wrote:

quoted

On Wed, Jun 28, 2017 at 07:20:19PM +0200, Lukas Wunner wrote:

quoted

--- 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?

With these checks present, searching for the properties can be optimized
away on ARM and skipped on x86 non-Macs.  (Each property query requires
decoding the _DSD Package and performing an O(n) search of the properties.)

Well, you add dmi_match() that gets called every time and I was under
the impression that we already performed _DSD decode when the property
set was initially parsed.

Those checks just uglify the code IMHO.

No strong feelings though, so up to Rafael to decide :-)
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