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authorHans de Goede <hdegoede@redhat.com>2023-01-10 16:30:28 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2023-01-10 20:23:48 +0100
commitf64e4275ef7407d5c3eca20436519bbd1f796e40 (patch)
tree44fa2f995c4a6e4f795434f930730688a5a35e09
parentb7bfaa761d760e72a969d116517eaa12e404c262 (diff)
downloadlinux-f64e4275ef7407d5c3eca20436519bbd1f796e40.tar.bz2
ACPI: Fix selecting wrong ACPI fwnode for the iGPU on some Dell laptops
The Dell Latitude E6430 both with and without the optional NVidia dGPU has a bug in its ACPI tables which is causing Linux to assign the wrong ACPI fwnode / companion to the pci_device for the i915 iGPU. Specifically under the PCI root bridge there are these 2 ACPI Device()s : Scope (_SB.PCI0) { Device (GFX0) { Name (_ADR, 0x00020000) // _ADR: Address } ... Device (VID) { Name (_ADR, 0x00020000) // _ADR: Address ... Method (_DOS, 1, NotSerialized) // _DOS: Disable Output Switching { VDP8 = Arg0 VDP1 (One, VDP8) } Method (_DOD, 0, NotSerialized) // _DOD: Display Output Devices { ... } ... } } The non-functional GFX0 ACPI device is a problem, because this gets returned as ACPI companion-device by acpi_find_child_device() for the iGPU. This is a long standing problem and the i915 driver does use the ACPI companion for some things, but works fine without it. However since commit 63f534b8bad9 ("ACPI: PCI: Rework acpi_get_pci_dev()") acpi_get_pci_dev() relies on the physical-node pointer in the acpi_device and that is set on the wrong acpi_device because of the wrong acpi_find_child_device() return. This breaks the ACPI video code, leading to non working backlight control in some cases. Add a type.backlight flag, mark ACPI video bus devices with this and make find_child_checks() return a higher score for children with this flag set, so that it picks the right companion-device. Fixes: 63f534b8bad9 ("ACPI: PCI: Rework acpi_get_pci_dev()") Co-developed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Cc: 6.1+ <stable@vger.kernel.org> # 6.1+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--drivers/acpi/glue.c14
-rw-r--r--drivers/acpi/scan.c7
-rw-r--r--include/acpi/acpi_bus.h3
3 files changed, 19 insertions, 5 deletions
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 204fe94c7e45..a194f30876c5 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -75,7 +75,8 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
}
#define FIND_CHILD_MIN_SCORE 1
-#define FIND_CHILD_MAX_SCORE 2
+#define FIND_CHILD_MID_SCORE 2
+#define FIND_CHILD_MAX_SCORE 3
static int match_any(struct acpi_device *adev, void *not_used)
{
@@ -96,8 +97,17 @@ static int find_child_checks(struct acpi_device *adev, bool check_children)
return -ENODEV;
status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
- if (status == AE_NOT_FOUND)
+ if (status == AE_NOT_FOUND) {
+ /*
+ * Special case: backlight device objects without _STA are
+ * preferred to other objects with the same _ADR value, because
+ * it is more likely that they are actually useful.
+ */
+ if (adev->pnp.type.backlight)
+ return FIND_CHILD_MID_SCORE;
+
return FIND_CHILD_MIN_SCORE;
+ }
if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
return -ENODEV;
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 274344434282..0c6f06abe3f4 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1370,9 +1370,12 @@ static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
* Some devices don't reliably have _HIDs & _CIDs, so add
* synthetic HIDs to make sure drivers can find them.
*/
- if (acpi_is_video_device(handle))
+ if (acpi_is_video_device(handle)) {
acpi_add_id(pnp, ACPI_VIDEO_HID);
- else if (acpi_bay_match(handle))
+ pnp->type.backlight = 1;
+ break;
+ }
+ if (acpi_bay_match(handle))
acpi_add_id(pnp, ACPI_BAY_HID);
else if (acpi_dock_match(handle))
acpi_add_id(pnp, ACPI_DOCK_HID);
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index cd3b75e08ec3..e44be31115a6 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -230,7 +230,8 @@ struct acpi_pnp_type {
u32 hardware_id:1;
u32 bus_address:1;
u32 platform_id:1;
- u32 reserved:29;
+ u32 backlight:1;
+ u32 reserved:28;
};
struct acpi_device_pnp {