[PATCH 5.15 063/570] platform/x86: thinkpad_acpi: Fix errors reading battery thresholds

Greg Kroah-Hartman
2026-04-13T16:20:47Z

From: Jonathan Teh <jonathan.teh@outlook.com>

[ Upstream commit 53e977b1d50c46f2c4ec3865cd13a822f58ad3cd ]

Check whether the battery supports the relevant charge threshold before
reading the value to silence these errors:

thinkpad_acpi: acpi_evalf(BCTG, dd, ...) failed: AE_NOT_FOUND
ACPI: \_SB_.PCI0.LPC_.EC__.HKEY: BCTG: evaluate failed
thinkpad_acpi: acpi_evalf(BCSG, dd, ...) failed: AE_NOT_FOUND
ACPI: \_SB_.PCI0.LPC_.EC__.HKEY: BCSG: evaluate failed

when reading the charge thresholds via sysfs on platforms that do not
support them such as the ThinkPad T400.

Fixes: 2801b9683f74 ("thinkpad_acpi: Add support for battery thresholds")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=202619
Signed-off-by: Jonathan Teh <jonathan.teh@outlook.com>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://patch.msgid.link/MI0P293MB01967B206E1CA6F337EBFB12926CA@MI0P293MB0196.ITAP293.PROD.OUTLOOK.COM
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/platform/x86/thinkpad_acpi.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 89a8e074c16d0..43a4851d2de61 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -9460,14 +9460,16 @@ static int tpacpi_battery_get(int what, int battery, int *ret)
{
switch (what) {
case THRESHOLD_START:
- if ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_START, ret, battery))
+ if (!battery_info.batteries[battery].start_support ||
+ ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_START, ret, battery)))
return -ENODEV;

/* The value is in the low 8 bits of the response */
*ret = *ret & 0xFF;
return 0;
case THRESHOLD_STOP:
- if ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_STOP, ret, battery))
+ if (!battery_info.batteries[battery].stop_support ||
+ ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_STOP, ret, battery)))
return -ENODEV;
/* Value is in lower 8 bits */
*ret = *ret & 0xFF;
--
2.51.0