thermal: Add comment explaining test for critical temperature

The code testing if a temperature should be emulated or not is
not obvious. Add a comment explaining why this test is done.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 9599465abeac5a4b03e4006396d4e1b366ae2ac4..6a707789746beed907e359f34bc75d2e7e6a5227 100644 (file)
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -498,6 +498,11 @@ int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
                        }
                }
 
+               /*
+                * Only allow emulating a temperature when the real temperature
+                * is below the critical temperature so that the emulation code
+                * cannot hide critical conditions.
+                */
                if (!ret && *temp < crit_temp)
                        *temp = tz->emul_temperature;
        }