Most Bay and Cherry Trail devices use a generic DSDT with all possible peripheral devices present in the DSDT, with their _STA returning 0x00 or 0x0f based on AML variables which describe what is actually present on the board. Since ACPI device objects with a 0x00 status (not present) still get an entry under /sys/bus/acpi/devices, and those entry had an acpi:PNPID modalias, userspace would end up loading modules for non present hardware. This commit fixes this by leaving the modalias empty for non present devices. This results in 10 modules less being loaded with a generic distro kernel config on my Cherry Trail test-device (a GPD pocket). Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- drivers/acpi/device_sysfs.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c index 24418932612e..a041689e5701 100644 --- a/drivers/acpi/device_sysfs.c +++ b/drivers/acpi/device_sysfs.c @@ -146,6 +146,10 @@ static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias, int count; struct acpi_hardware_id *id; + /* Avoid unnecessarily loading modules for non present devices. */ + if (!acpi_device_is_present(acpi_dev)) + return 0; + /* * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the -- 2.14.2 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
