From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
The PNP0D80 ("Windows-compatible System Power Management Controller")
device ID is used for identifying the special device object providing
the LPI (Low-power S0 Idle) _DSM interface [1]. That device object
does not supply any operation regions, but it appears in _DEP lists
for other devices in the ACPI tables on some systems to enforce
specific enumeration ordering that does not matter in Linux.
For this reason, _DEP list entries pointing to the device object whose
_CID returns PNP0D80 need not be taken into account as real operation
region dependencies, so add that device ID to the list of device IDs
for which the matching _DEP list entries should be ignored.
Accordingly, update the function used for matching device IDs in that
list to allow it to check _CID as well as _HID and rename it to
acpi_info_matches_ids().
Link: https://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf # [1]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/scan.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -719,25 +719,40 @@ int acpi_device_add(struct acpi_device *
/* --------------------------------------------------------------------------
Device Enumeration
-------------------------------------------------------------------------- */
-static bool acpi_info_matches_hids(struct acpi_device_info *info,
- const char * const hids[])
+static bool acpi_info_matches_ids(struct acpi_device_info *info,
+ const char * const ids[])
{
+ struct acpi_pnp_device_id_list *cid_list = NULL;
int i;
if (!(info->valid & ACPI_VALID_HID))
return false;
- for (i = 0; hids[i]; i++) {
- if (!strcmp(info->hardware_id.string, hids[i]))
+ if (info->valid & ACPI_VALID_CID)
+ cid_list = &info->compatible_id_list;
+
+ for (i = 0; ids[i]; i++) {
+ int j;
+
+ if (!strcmp(info->hardware_id.string, ids[i]))
return true;
+
+ if (!cid_list)
+ continue;
+
+ for (j = 0; j < cid_list->count; j++) {
+ if (!strcmp(cid_list->ids[j].string, ids[i]))
+ return true;
+ }
}
return false;
}
/* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
-static const char * const acpi_ignore_dep_hids[] = {
+static const char * const acpi_ignore_dep_ids[] = {
"INT3396", /* Windows System Power Management Controller */
+ "PNP0D80", /* Windows-compatible System Power Management Controller */
NULL
};
@@ -1857,7 +1872,7 @@ static void acpi_device_dep_initialize(s
continue;
}
- skip = acpi_info_matches_hids(info, acpi_ignore_dep_hids);
+ skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
kfree(info);
if (skip)
