[PATCH 6.12.y] hwmon: (acpi_power_meter) Fix 18.45 TW bug

[Sasha Levin <sashal@kernel.org>]

From: Armin Wolf <W_Armin@gmx.de>

[ Upstream commit 0b6eda22f9ab67ddb2a872b0c3fc578ad9f4e27e ]

The ACPI specification says:

"If an error occurs while obtaining the meter reading or if the value
is not available then an Integer with all bits set is returned"

This integer can also be 64-bit wide on ACPI 2.0 and later systems,
so we have to check for that too.

Compile-tested only.

Reported-by: Grant Slater <github@firefishy.com>
Closes: https://github.com/lm-sensors/lm-sensors/issues/460
Fixes: 1fefca6c57fb ("hwmon: (acpi_power_meter) Fix 4.29 MW bug")
Cc: stable@vger.kernel.org
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/20261006234618.10943-1-W_Armin@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[ sashal: adapted the power_meter_read() change to show_power() using its existing resource variable ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hwmon/acpi_power_meter.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
index 6c8a9c863528e..eedcfc9d96c6c 100644
--- a/drivers/hwmon/acpi_power_meter.c
+++ b/drivers/hwmon/acpi_power_meter.c
@@ -10,6 +10,7 @@
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/jiffies.h>
+#include <linux/limits.h>
 #include <linux/mutex.h>
 #include <linux/dmi.h>
 #include <linux/slab.h>
@@ -31,7 +32,12 @@
 #define POWER_METER_CAN_NOTIFY	(1 << 3)
 #define POWER_METER_IS_BATTERY	(1 << 8)
 #define UNKNOWN_HYSTERESIS	0xFFFFFFFF
-#define UNKNOWN_POWER		0xFFFFFFFF
+/*
+ * ACPI integers can either be 32-bit or 64-bit wide, so
+ * we have to check for both values.
+ */
+#define UNKNOWN_POWER_32	U32_MAX
+#define UNKNOWN_POWER_64	U64_MAX
 
 #define METER_NOTIFY_CONFIG	0x80
 #define METER_NOTIFY_TRIP	0x81
@@ -349,7 +355,7 @@ static ssize_t show_power(struct device *dev,
 	update_meter(resource);
 	mutex_unlock(&resource->lock);
 
-	if (resource->power == UNKNOWN_POWER)
+	if (resource->power == UNKNOWN_POWER_32 || resource->power == UNKNOWN_POWER_64)
 		return -ENODATA;
 
 	return sprintf(buf, "%llu\n", resource->power * 1000);
-- 
2.53.0