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| author | Hans de Goede <hdegoede@redhat.com> | 2023-01-10 16:30:28 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2023-01-10 20:23:48 +0100 |
| commit | f64e4275ef7407d5c3eca20436519bbd1f796e40 (patch) | |
| tree | 44fa2f995c4a6e4f795434f930730688a5a35e09 /include | |
| parent | b7bfaa761d760e72a969d116517eaa12e404c262 (diff) | |
| download | linux-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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/acpi/acpi_bus.h | 3 |
1 files changed, 2 insertions, 1 deletions
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 { |