Merge tag 'pm+acpi-4.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "These are fixes on top of the previous PM+ACPI pull requests
  (including one fix for a 4.1 regression) and two commits adding
  _CLS-based device enumeration support to the ACPI core and the ATA
  subsystem that waited for the latest ACPICA changes to be merged.

  Specifics:

   - Fix for an ACPI resources management regression introduced during
     the 4.1 cycle (that unfortunately went into -stable) effectively
     reverting the bad commit along with the recent fixups on top of it
     and using an alternative approach to address the underlying issue
     (Rafael J Wysocki).

   - Fix for a memory leak and an incorrect return value in an error
     code path in the ACPI LPSS (Low-Power Subsystem) driver (Rafael J
     Wysocki).

   - Fix for a leftover dangling pointer in an error code path in the
     new wakeup IRQ support code (Rafael J Wysocki).

   - Fix to prevent infinite loops (due to errors in other places) from
     happening in the core generic PM domains support code (Geert
     Uytterhoeven).

   - Hibernation documentation update/clarification (Uwe Geuder).

   - Support for _CLS-based device enumeration in the ACPI core and in
     the ATA subsystem (Suravee Suthikulpanit)"

* tag 'pm+acpi-4.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / wakeirq: Avoid setting power.wakeirq too hastily
  ata: ahci_platform: Add ACPI _CLS matching
  ACPI / scan: Add support for ACPI _CLS device matching
  PM / hibernate: clarify resume documentation
  PM / Domains: Avoid infinite loops in attach/detach code
  ACPI / LPSS: Fix up acpi_lpss_create_device()
  ACPI / PNP: Reserve ACPI resources at the fs_initcall_sync stage

2 files changed, 32 insertions, 2 deletions

diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
index eff7de1fc82e..e70fcd12eeeb 100644
--- a/scripts/mod/devicetable-offsets.c
+++ b/scripts/mod/devicetable-offsets.c
@@ -63,6 +63,8 @@ int main(void)
 
         DEVID(acpi_device_id);
         DEVID_FIELD(acpi_device_id, id);
+        DEVID_FIELD(acpi_device_id, cls);
+        DEVID_FIELD(acpi_device_id, cls_msk);
 
         DEVID(pnp_device_id);
         DEVID_FIELD(pnp_device_id, id);
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 84c86f3cd6cd..5f2088209132 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -523,12 +523,40 @@ static int do_serio_entry(const char *filename,
 }
 ADD_TO_DEVTABLE("serio", serio_device_id, do_serio_entry);
 
-/* looks like: "acpi:ACPI0003 or acpi:PNP0C0B" or "acpi:LNXVIDEO" */
+/* looks like: "acpi:ACPI0003" or "acpi:PNP0C0B" or "acpi:LNXVIDEO" or
+ *             "acpi:bbsspp" (bb=base-class, ss=sub-class, pp=prog-if)
+ *
+ * NOTE: Each driver should use one of the following : _HID, _CIDs
+ *       or _CLS. Also, bb, ss, and pp can be substituted with ??
+ *       as don't care byte.
+ */
 static int do_acpi_entry(const char *filename,
                         void *symval, char *alias)
 {
         DEF_FIELD_ADDR(symval, acpi_device_id, id);
-        sprintf(alias, "acpi*:%s:*", *id);
+        DEF_FIELD_ADDR(symval, acpi_device_id, cls);
+        DEF_FIELD_ADDR(symval, acpi_device_id, cls_msk);
+
+        if (id && strlen((const char *)*id))
+                sprintf(alias, "acpi*:%s:*", *id);
+        else if (cls) {
+                int i, byte_shift, cnt = 0;
+                unsigned int msk;
+
+                sprintf(&alias[cnt], "acpi*:");
+                cnt = 6;
+                for (i = 1; i <= 3; i++) {
+                        byte_shift = 8 * (3-i);
+                        msk = (*cls_msk >> byte_shift) & 0xFF;
+                        if (msk)
+                                sprintf(&alias[cnt], "%02x",
+                                        (*cls >> byte_shift) & 0xFF);
+                        else
+                                sprintf(&alias[cnt], "??");
+                        cnt += 2;
+                }
+                sprintf(&alias[cnt], ":*");
+        }
         return 1;
 }
 ADD_TO_DEVTABLE("acpi", acpi_device_id, do_acpi_entry);