Don't create a device_t object or parse current resources (via _CRS) for

ACPI Device() objects that do not have any device IDs available via the
_HID or _CID methods.  Without a device ID a device driver cannot attach
to the device anyway.  Namespace objects that are devices but not of
type ACPI_TYPE_DEVICE are not affected.

A few BIOSes have also attached a _CRS method to a PCI device to
allocate resources that are not managed via a BAR.  With the previous
code those resources are allocated from acpi0 directly which can interfere
with the new PCI-PCI bridge driver (since the PCI device in question may
be behind a bridge and its resources should be allocated from that
bridge's windows instead).  The resources were also orphaned and
and would end up associated with some other random device whose device_t
reused the pointer of the original ACPI-enumerated device (after it was
free'd by the ACPI PCI bus driver) in devinfo output which was confusing.
If we want to handle _CRS on PCI devices we can adjust the ACPI PCI bus
driver to do that in the future and associate the resources with the
proper device object respecting PCI-PCI bridges, etc.

Note that with this change the ACPI PCI bus driver no longer has to
delete ACPI-enumerated device_t devices that mirror PCI devices since
they should in general not exist.  There are rare cases when a BIOS
will give a PCI device a _HID (e.g. I've seen a PCI-ISA bridge given
a _HID for a system resource device).  In that case we leave both the
ACPI and PCI-enumerated device_t objects around just as in the previous
code.

2 files changed, 38 insertions, 20 deletions

diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index 3cef351..84f65bd 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -151,6 +151,7 @@ static ACPI_STATUS acpi_sleep_disable(struct acpi_softc *sc);
 static ACPI_STATUS acpi_EnterSleepState(struct acpi_softc *sc, int state);
 static void	acpi_shutdown_final(void *arg, int howto);
 static void	acpi_enable_fixed_events(struct acpi_softc *sc);
+static BOOLEAN	acpi_has_hid(ACPI_HANDLE handle);
 static int	acpi_wake_sleep_prep(ACPI_HANDLE handle, int sstate);
 static int	acpi_wake_run_prep(ACPI_HANDLE handle, int sstate);
 static int	acpi_wake_prep_walk(int sstate);
@@ -1855,6 +1856,13 @@ acpi_probe_child(ACPI_HANDLE handle, UINT32 level, void *context, void **status)
 		break;
 	    if (acpi_parse_prw(handle, &prw) == 0)
 		AcpiSetupGpeForWake(handle, prw.gpe_handle, prw.gpe_bit);
+
+	    /*
+	     * Ignore devices that do not have a _HID or _CID.  They should
+	     * be discovered by other buses (e.g. the PCI bus driver).
+	     */
+	    if (!acpi_has_hid(handle))
+		break;
 	    /* FALLTHROUGH */
 	case ACPI_TYPE_PROCESSOR:
 	case ACPI_TYPE_THERMAL:
@@ -2043,6 +2051,30 @@ acpi_BatteryIsPresent(device_t dev)
 }
 
 /*
+ * Returns true if a device has at least one valid device ID.
+ */
+static BOOLEAN
+acpi_has_hid(ACPI_HANDLE h)
+{
+    ACPI_DEVICE_INFO	*devinfo;
+    BOOLEAN		ret;
+
+    if (h == NULL ||
+	ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
+	return (FALSE);
+
+    ret = FALSE;
+    if ((devinfo->Valid & ACPI_VALID_HID) != 0)
+	ret = TRUE;
+    else if ((devinfo->Valid & ACPI_VALID_CID) != 0)
+	if (devinfo->CompatibleIdList.Count > 0)
+	    ret = TRUE;
+
+    AcpiOsFree(devinfo);
+    return (ret);
+}
+
+/*
  * Match a HID string against a handle
  */
 BOOLEAN
diff --git a/sys/dev/acpica/acpi_pci.c b/sys/dev/acpica/acpi_pci.c
index 76cbacb..44db74a 100644
--- a/sys/dev/acpica/acpi_pci.c
+++ b/sys/dev/acpica/acpi_pci.c
@@ -209,38 +209,24 @@ acpi_pci_update_device(ACPI_HANDLE handle, device_t pci_child)
 	device_t child;
 
 	/*
-	 * Lookup and remove the unused device that acpi0 creates when it walks
-	 * the namespace creating devices.
+	 * Occasionally a PCI device may show up as an ACPI device
+	 * with a _HID.  (For example, the TabletPC TC1000 has a
+	 * second PCI-ISA bridge that has a _HID for an
+	 * acpi_sysresource device.)  In that case, leave ACPI-CA's
+	 * device data pointing at the ACPI-enumerated device.
 	 */
 	child = acpi_get_device(handle);
 	if (child != NULL) {
-		if (device_is_alive(child)) {
-			/*
-			 * The TabletPC TC1000 has a second PCI-ISA bridge
-			 * that has a _HID for an acpi_sysresource device.
-			 * In that case, leave ACPI-CA's device data pointing
-			 * at the ACPI-enumerated device.
-			 */
-			device_printf(child,
-			    "Conflicts with PCI device %d:%d:%d\n",
-			    pci_get_bus(pci_child), pci_get_slot(pci_child),
-			    pci_get_function(pci_child));
-			return;
-		}
 		KASSERT(device_get_parent(child) ==
 		    devclass_get_device(devclass_find("acpi"), 0),
 		    ("%s: child (%s)'s parent is not acpi0", __func__,
 		    acpi_name(handle)));
-		device_delete_child(device_get_parent(child), child);
+		return;
 	}
 
 	/*
 	 * Update ACPI-CA to use the PCI enumerated device_t for this handle.
 	 */
-	status = AcpiDetachData(handle, acpi_fake_objhandler);
-	if (ACPI_FAILURE(status))
-		printf("WARNING: Unable to detach object data from %s - %s\n",
-		    acpi_name(handle), AcpiFormatException(status));
 	status = AcpiAttachData(handle, acpi_fake_objhandler, pci_child);
 	if (ACPI_FAILURE(status))
 		printf("WARNING: Unable to attach object data to %s - %s\n",