[PATCH v3 2/4] ACPI: battery: Evaluate battery methods exclusively

From: Ali Ahmet Memiş

Date: Sun Oct 18 2026 - 08:23:50 EST


On ThinkPad P1 Gen2 and P53, INT3403 _TMP switches the EC page selector
without taking the AML mutex the battery methods use, so _BIX and _BST
running at the same time can read the wrong page. Since commit d33e89d12295
("thermal: core: Suspend thermal zones later and resume them earlier")
this happens on most resumes.

Evaluate the battery methods with acpi_evaluate_object_exclusive().

Fixes: d33e89d12295 ("thermal: core: Suspend thermal zones later and resume them earlier")
Reported-by: Charis Stratakis <c.stratakis@xxxxxxxxx>
Closes: https://lore.kernel.org/all/37N_jFulf7n-Z55NfKfE71C_wVPxYvZ0xD_iRUg2fXu7TypDiF5PStQ6siSfVBih6fThg5WoPes8U5ZQpfVm_teMFcUGXFxz2DdMbfSWuws=@proton.me/
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ali Ahmet Memiş <aliamemis@xxxxxxxxxxx>
Reviewed-by: Hans de Goede <johannes.goede@xxxxxxxxxxxxxxxx>
Reviewed-by: Rong Zhang <i@xxxxxxxx>
---
drivers/acpi/battery.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 670853ec3a4d..7169ac7e83f3 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -583,9 +583,8 @@ static int acpi_battery_get_info(struct acpi_battery *battery)
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_status status = AE_ERROR;

- status = acpi_evaluate_object(battery->device->handle,
- use_bix ? "_BIX":"_BIF",
- NULL, &buffer);
+ status = acpi_evaluate_object_exclusive(battery->device->handle,
+ use_bix ? "_BIX" : "_BIF", NULL, &buffer);

if (ACPI_FAILURE(status)) {
acpi_handle_info(battery->device->handle,
@@ -624,8 +623,7 @@ static int acpi_battery_get_state(struct acpi_battery *battery)
msecs_to_jiffies(cache_time)))
return 0;

- status = acpi_evaluate_object(battery->device->handle, "_BST",
- NULL, &buffer);
+ status = acpi_evaluate_object_exclusive(battery->device->handle, "_BST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
acpi_handle_info(battery->device->handle,
"_BST evaluation failed: %s",
@@ -675,8 +673,8 @@ static int acpi_battery_set_alarm(struct acpi_battery *battery)
!test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
return -ENODEV;

- status = acpi_execute_simple_method(battery->device->handle, "_BTP",
- battery->alarm);
+ status = acpi_execute_simple_method_exclusive(battery->device->handle, "_BTP",
+ battery->alarm);
if (ACPI_FAILURE(status))
return -ENODEV;

--
2.55.0