Merge tag 'acpi-7.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI support fixes from Rafael Wysocki:
 "These fix an MFD child automatic modprobe issue introduced recently,
  an ACPI processor driver issue introduced by a previous fix and an
  ACPICA issue causing confusing messages regarding _DSM arguments to be
  printed:

   - Update the format of the last argument of _DSM to avoid printing
     confusing error messages in some cases (Saket Dumbre)

   - Fix MFD child automatic modprobe issue by removing a stale check
     from acpi_companion_match() (Pratap Nirujogi)

   - Prevent possible use-after-free in acpi_processor_errata_piix4()
     from occurring by rearranging the code to print debug messages
     while holding references to relevant device objects (Rafael
     Wysocki)"

* tag 'acpi-7.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: bus: Fix MFD child automatic modprobe issue
  ACPI: processor: Fix previous acpi_processor_errata_piix4() fix
  ACPICA: Update the format of Arg3 of _DSM

Author: torvalds

drivers/acpi/acpi_processor.c

@@ -113,6 +113,10 @@ static int acpi_processor_errata_piix4(struct pci_dev *dev)
 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
 		if (ide_dev) {
 			errata.piix4.bmisx = pci_resource_start(ide_dev, 4);
+			if (errata.piix4.bmisx)
+				dev_dbg(&ide_dev->dev,
+					"Bus master activity detection (BM-IDE) erratum enabled\n");
+
 			pci_dev_put(ide_dev);
 		}
 
@@ -131,20 +135,17 @@ static int acpi_processor_errata_piix4(struct pci_dev *dev)
 		if (isa_dev) {
 			pci_read_config_byte(isa_dev, 0x76, &value1);
 			pci_read_config_byte(isa_dev, 0x77, &value2);
-			if ((value1 & 0x80) || (value2 & 0x80))
+			if ((value1 & 0x80) || (value2 & 0x80)) {
 				errata.piix4.fdma = 1;
+				dev_dbg(&isa_dev->dev,
+					"Type-F DMA livelock erratum (C3 disabled)\n");
+			}
 			pci_dev_put(isa_dev);
 		}
 
 		break;
 	}
 
-	if (ide_dev)
-		dev_dbg(&ide_dev->dev, "Bus master activity detection (BM-IDE) erratum enabled\n");
-
-	if (isa_dev)
-		dev_dbg(&isa_dev->dev, "Type-F DMA livelock erratum (C3 disabled)\n");
-
 	return 0;
 }
 

drivers/acpi/acpica/acpredef.h

@@ -451,7 +451,7 @@ const union acpi_predefined_info acpi_gbl_predefined_methods[] = {
 
 	{{"_DSM",
 	  METHOD_4ARGS(ACPI_TYPE_BUFFER, ACPI_TYPE_INTEGER, ACPI_TYPE_INTEGER,
-		       ACPI_TYPE_ANY | ACPI_TYPE_PACKAGE) |
+		       ACPI_TYPE_PACKAGE | ACPI_TYPE_ANY) |
 		       ARG_COUNT_IS_MINIMUM,
 	  METHOD_RETURNS(ACPI_RTYPE_ALL)}},	/* Must return a value, but it can be of any type */
 

drivers/acpi/bus.c

@@ -818,9 +818,6 @@ const struct acpi_device *acpi_companion_match(const struct device *dev)
 	if (list_empty(&adev->pnp.ids))
 		return NULL;
 
-	if (adev->pnp.type.backlight)
-		return adev;
-
 	return acpi_primary_dev_companion(adev, dev);
 }