From: Jeff Wu Date: Wed, 29 May 2013 06:31:30 +0000 (+0000) Subject: ACPI: add _STA evaluation at do_acpi_find_child() X-Git-Tag: next-20130607~73^2~13^2~2 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c2298aec694f3f33c986262b20667ab006c1dba5;p=karo-tx-linux.git ACPI: add _STA evaluation at do_acpi_find_child() Once do_acpi_find_child() has found the first matching handle, it makes the acpi_get_child() loop stop and return that handle. On some platforms, though, there are multiple devices with the same value of "_ADR" in the same namespace scope, and if one of them is enabled, the others will be disabled. For example: Address : 0x1FFFF ; path : SB_PCI0.SATA.DEV0 Address : 0x1FFFF ; path : SB_PCI0.SATA.DEV1 Address : 0x1FFFF ; path : SB_PCI0.SATA.DEV2 If DEV0 and DEV1 are disabled and DEV2 is enabled, the handle of DEV2 should be returned, but actually the function always returns the handle of DEV0. To address that issue, make do_acpi_find_child() evaluate _STA to check the device status. If a matching device object exists, but is disabled, acpi_get_child() will continue to walk the namespace in the hope of finding an enabled one. If one is found, its handle will be returned, but otherwise the function will return the handle of the disabled object found before (in case it is enabled going forward). [rjw: Changelog] Signed-off-by: Jeff Wu Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index 40a84cc6740c..51ca764cffea 100644 --- a/drivers/acpi/glue.c +++ b/drivers/acpi/glue.c @@ -81,13 +81,15 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev) static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used, void *addr_p, void **ret_p) { - unsigned long long addr; + unsigned long long addr, sta; acpi_status status; status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr); if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) { *ret_p = handle; - return AE_CTRL_TERMINATE; + status = acpi_bus_get_status_handle(handle, &sta); + if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_ENABLED)) + return AE_CTRL_TERMINATE; } return AE_OK; }