Since ACPICA commit f005ee6b90d1 / Linux commit 2d3349de8072
("ACPICA: Namespace: Reorder \_SB._INI to make sure it is evaluated
before _REG evaluations") acpi_initialize_objects() calls \_SB._INI
before executing _REG OpRegion methods, because the _REG methods may
rely on initialization done by this _INI method.
In many DSDTs the \_SB.PC00._INI / \_SB.PCI0._INI methods set an OSYS
global variable based on _OSI evaluations.
In some cases there are _REG methods which depend on the OSYS value and
before this change ACPICA would run these _REG methods before running
_SB.PC00._INI / \_SB.PCI0._INI causing issues.
2 examples of problems caused by running _REG methods before these
_INI methods are:
1. on a "Lenovo IdeaPad 5 15ITL05" \_SB.PC00.LPCB.EC0._REG gets
evaluated before \_SB.PC00._INI and that _REG contains:
If ((OSYS == 0x07DF))
{
Local0 = 0x06
}
If ((Acquire (LFCM, 0xA000) == Zero))
{
OSTY = Local0
...
With OSTY being a SystemMemory OpRegion field, due to the _INI running
too late, Local0 stays at 0. Causing OSTY to be set to 0 instead of 6,
which causes the brightness up/down keys to not work:
https://bugzilla.kernel.org/show_bug.cgi?id=214899
2. On a "Lenovo Thinkbook 14-ILL" \\_SB_.PCI0.I2C0._REG gets
evaluated before \_SB.PCI0._INI and that _REG contains:
If ((OSYS == 0x07DF))
{
...
LNUX = Zero
TPID = 0x4E
}
else
{
LNUX = One
TPID = 0xBB
}
And then later on the TPID value gets used to decide for which of multiple
devices describing the touchpad _STA should return 0xF and the one which
gets enabled by TPID=0xBB is broken, causing to the touchpad to not work:
https://bugzilla.redhat.com/show_bug.cgi?id=1842039
Fix these issues by adding \_SB.PC00._INI / \_SB.PCI0._INI to the list of
_INI methods to run early (before executing _REG methods).
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/acpi/acpica/nsinit.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/acpica/nsinit.c b/drivers/acpi/acpica/nsinit.c
index f5364d44fdb8..db66df28e4fc 100644
--- a/drivers/acpi/acpica/nsinit.c
+++ b/drivers/acpi/acpica/nsinit.c
@@ -105,6 +105,10 @@ static acpi_string const acpi_ns_early_init_paths[] = {
/* There appears to be a strict order requirement for \_SB._INI,
* which should be evaluated before any _REG evaluations. */
"\\_SB",
+ /* \_SB.PC00._INI or \_SB.PCI0.INI may use \_OSI to set an OSYS global
+ * variable used in _REG methods. */
+ "\\_SB.PC00",
+ "\\_SB.PCI0",
};
acpi_status acpi_ns_early_initialize_devices(void)
@@ -519,7 +523,7 @@ acpi_ns_find_ini_methods(acpi_handle obj_handle,
static u8 acpi_ns_is_early_init_device(struct acpi_namespace_node *device_node)
{
- char path[ACPI_PATH_SEGMENT_LENGTH + 2];
+ char path[ACPI_PATH_SEGMENT_LENGTH * 2 + 2];
int i;
acpi_ns_build_normalized_path(device_node, path, sizeof(path), TRUE);
--
2.36.0
