ACPICA: Remove calling of _STA from acpi_get_object_info()

As the documentatuon above its declaration indicates, acpi_get_object_info()
is intended for early probe usage and as such should not call any methods
which may rely on op_regions, before this commit it was also calling _STA,
which on some systems does rely on op_regions.

Calling _STA before things are ready leads to errors such as these
(under Linux, on some hardware):

[    0.123579] ACPI Error: No handler for Region [ECRM] (00000000ba9edc4c)
               [generic_serial_bus] (20170831/evregion-166)
[    0.123601] ACPI Error: Region generic_serial_bus (ID=9) has no handler
               (20170831/exfldio-299)
[    0.123618] ACPI Error: Method parse/execution failed
               \_SB.I2C1.BAT1._STA, AE_NOT_EXIST (20170831/psparse-550)

End 2015 support for the _SUB method was removed for exactly the same
reason. Removing current_status from struct acpi_device_info only has a limited
impact. Within ACPICA it is only used by 2 debug messages, both
of which are modified to no longer print it with this commit.

Outside of ACPICA, there was one user in Linux, which has been patched to
no longer use current_status in Torvald's current master.

I've not checked if free_BSD or others are using the current_status field.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 5 insertions, 16 deletions

diff --git a/drivers/acpi/acpica/nsxfname.c b/drivers/acpi/acpica/nsxfname.c
index e9603fc9586c..c36975c1d1a9 100644
--- a/drivers/acpi/acpica/nsxfname.c
+++ b/drivers/acpi/acpica/nsxfname.c
@@ -241,7 +241,7 @@ static char *acpi_ns_copy_device_id(struct acpi_pnp_device_id *dest,
  *              namespace node and possibly by running several standard
  *              control methods (Such as in the case of a device.)
  *
- * For Device and Processor objects, run the Device _HID, _UID, _CID, _STA,
+ * For Device and Processor objects, run the Device _HID, _UID, _CID,
  * _CLS, _ADR, _sx_w, and _sx_d methods.
  *
  * Note: Allocates the return buffer, must be freed by the caller.
@@ -250,8 +250,9 @@ static char *acpi_ns_copy_device_id(struct acpi_pnp_device_id *dest,
  * discovery namespace traversal. Therefore, no complex methods can be
  * executed, especially those that access operation regions. Therefore, do
  * not add any additional methods that could cause problems in this area.
- * this was the fate of the _SUB method which was found to cause such
- * problems and was removed (11/2015).
+ * Because of this reason support for the following methods has been removed:
+ * 1) _SUB method was removed (11/2015)
+ * 2) _STA method was removed (02/2018)
  *
  ******************************************************************************/
 
@@ -369,25 +370,13 @@ acpi_get_object_info(acpi_handle handle,
 	if ((type == ACPI_TYPE_DEVICE) || (type == ACPI_TYPE_PROCESSOR)) {
 		/*
 		 * Get extra info for ACPI Device/Processor objects only:
-		 * Run the _STA, _ADR and, sx_w, and _sx_d methods.
+		 * Run the _ADR and, sx_w, and _sx_d methods.
 		 *
 		 * Notes: none of these methods are required, so they may or may
 		 * not be present for this device. The Info->Valid bitfield is used
 		 * to indicate which methods were found and run successfully.
-		 *
-		 * For _STA, if the method does not exist, then (as per the ACPI
-		 * specification), the returned current_status flags will indicate
-		 * that the device is present/functional/enabled. Otherwise, the
-		 * current_status flags reflect the value returned from _STA.
 		 */
 
-		/* Execute the Device._STA method */
-
-		status = acpi_ut_execute_STA(node, &info->current_status);
-		if (ACPI_SUCCESS(status)) {
-			valid |= ACPI_VALID_STA;
-		}
-
 		/* Execute the Device._ADR method */
 
 		status = acpi_ut_evaluate_numeric_object(METHOD_NAME__ADR, node,