[SRU][Q:linux][PATCH 5/5] thermal: intel: int340x: Power Slider: Validate slider_balance range

[Thibault Ferrante]

From: Srinivas Pandruvada <srinivas.pandruvada at linux.intel.com>

BugLink: https://bugs.launchpad.net/bugs/2127187

When the module parameter slider_balance is set to the performance
slider value of 0, the SoC slider profile switches to the performance
mode.

This can cause the Linux power-profiles-daemon to change the system
power mode to performance from balanced mode. This happens when there
is only one platform profile registered as there will be no conflict
with other platform profiles.

Same issue occurs when the slider_balance is set to the power-saver
slider value.

Prevent module parameter slider_balance from overlapping with
performance and power-saver slider values by adding range validation.

Return an error when an invalid value is provided.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada at linux.intel.com>
Link: https://patch.msgid.link/20250923205631.3056590-1-srinivas.pandruvada@linux.intel.com
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
(cherry picked from commit 5cf952c54f3546f904ded645aecc1788d1090bd2)
Signed-off-by: Thibault Ferrante <thibault.ferrante at canonical.com>
---
 .../intel/int340x_thermal/processor_thermal_soc_slider.c       | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_soc_slider.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_soc_slider.c
index 20d70cb01542..49ff3bae7271 100644
--- a/drivers/thermal/intel/int340x_thermal/processor_thermal_soc_slider.c
+++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_soc_slider.c
@@ -67,7 +67,8 @@ static int slider_def_balance_set(const char *arg, const struct kernel_param *kp
 
 	ret = kstrtou8(arg, 16, &slider_val);
 	if (!ret) {
-		if (slider_val > SOC_SLIDER_VALUE_MAXIMUM)
+		if (slider_val <= slider_values[SOC_POWER_SLIDER_PERFORMANCE] ||
+		    slider_val >= slider_values[SOC_POWER_SLIDER_POWERSAVE])
 			return -EINVAL;
 
 		slider_balanced_param = slider_val;
-- 
2.48.1