Fix oinkmaster patch.

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.39 / patches.arch / 0000-ACPI-video-Ignore-devices-not-present.patch

From: Thomas Renninger <trenn@suse.de>
Subject: ACPI: video: Ignore devices that aren't present in hardware
Patch-Mainline: queued for .28 in Len's/ak's ACPI tree

commit ad9ed8385ed6ec5be8da7094db911c824258ceec

    This is a reimplemention of commit
    0119509c4fbc9adcef1472817fda295334612976
    from Matthew Garrett <mjg59@srcf.ucam.org>
    
    This patch got removed because of a regression: ThinkPads with a
    Intel graphics card and an Integrated Graphics Device BIOS implementation
    stopped working.
    In fact, they only worked because the ACPI device of the discrete, the
    wrong one, got used (via int10). So ACPI functions were poking on the wrong
    hardware used which is a sever bug.
    The next patch provides support for above ThinkPads to be able to
    switch brightness via the legacy thinkpad_acpi driver and automatically
    detect when to use it.
    
    Original commit message from Matthew Garrett:
        Vendors often ship machines with a choice of integrated or discrete
        graphics, and use the same DSDT for both. As a result, the ACPI video
        module will locate devices that may not exist on this specific platform.
        Attempt to determine whether the device exists or not, and abort the
        device creation if it doesn't.
    
    http://bugzilla.kernel.org/show_bug.cgi?id=9614
    
    Signed-off-by: Thomas Renninger <trenn@suse.de>
    Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
 drivers/acpi/glue.c     |   40 ++++++++++++++++++++++++++++++++++++++++
 drivers/acpi/video.c    |    7 ++++++-
 include/acpi/acpi_bus.h |    2 ++
 3 files changed, 48 insertions(+), 1 deletion(-)

--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -140,6 +140,46 @@ struct device *acpi_get_physical_device(
 
 EXPORT_SYMBOL(acpi_get_physical_device);
 
+/* ToDo: When a PCI bridge is found, return the PCI device behind the bridge
+ *       This should work in general, but did not on a Lenovo T61 for the
+ *	 graphics card. But this must be fixed when the PCI device is
+ *       bound and the kernel device struct is attached to the acpi device
+ * Note: A success call will increase reference count by one
+ *       Do call put_device(dev) on the returned device then
+ */
+struct device *acpi_get_physical_pci_device(acpi_handle handle)
+{
+	struct device *dev;
+	long long device_id;
+	acpi_status status;
+
+	status =
+		acpi_evaluate_integer(handle, "_ADR", NULL, &device_id);
+
+	if (ACPI_FAILURE(status))
+		return NULL;
+
+	/* We need to attempt to determine whether the _ADR refers to a
+	   PCI device or not. There's no terribly good way to do this,
+	   so the best we can hope for is to assume that there'll never
+	   be a device in the host bridge */
+	if (device_id >= 0x10000) {
+		/* It looks like a PCI device. Does it exist? */
+		dev = acpi_get_physical_device(handle);
+	} else {
+		/* It doesn't look like a PCI device. Does its parent
+		   exist? */
+		acpi_handle phandle;
+		if (acpi_get_parent(handle, &phandle))
+			return NULL;
+		dev = acpi_get_physical_device(phandle);
+	}
+	if (!dev)
+		return NULL;
+	return dev;
+}
+EXPORT_SYMBOL(acpi_get_physical_pci_device);
+
 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 {
 	struct acpi_device *acpi_dev;
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -862,11 +862,16 @@ static void acpi_video_bus_find_cap(stru
 static int acpi_video_bus_check(struct acpi_video_bus *video)
 {
 	acpi_status status = -ENOENT;
-
+	struct device *dev;
 
 	if (!video)
 		return -EINVAL;
 
+	dev = acpi_get_physical_pci_device(video->device->handle);
+	if (!dev)
+		return -ENODEV;
+	put_device(dev);
+
 	/* Since there is no HID, CID and so on for VGA driver, we have
 	 * to check well known required nodes.
 	 */
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -373,6 +373,8 @@ struct acpi_bus_type {
 int register_acpi_bus_type(struct acpi_bus_type *);
 int unregister_acpi_bus_type(struct acpi_bus_type *);
 struct device *acpi_get_physical_device(acpi_handle);
+struct device *acpi_get_physical_pci_device(acpi_handle);
+
 /* helper */
 acpi_handle acpi_get_child(acpi_handle, acpi_integer);
 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int, unsigned int);