thermal: fix cpu_cooling max_level behavior

As per Documentation/thermal/sysfs-api.txt, max_level
is an index, not a counter. Thus, in case a CPU has
3 valid frequencies, max_level is expected to be 2, for instance.

The current code makes max_level == number of valid frequencies,
which is bogus. This patch fix the cpu_cooling device by
ranging max_level properly.

Reported-by: Carlos Hernandez <ceh@ti.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index 02a46f23d14c..cc556a8e2842 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -173,6 +173,8 @@ static int get_property(unsigned int cpu, unsigned long input,
                 freq = table[i].frequency;
                 max_level++;
         }
+        /* max_level is an index, not a counter */
+        max_level--;
 
         /* get max level */
         if (property == GET_MAXL) {
@@ -181,7 +183,7 @@ static int get_property(unsigned int cpu, unsigned long input,
         }
 
         if (property == GET_FREQ)
-                level = descend ? input : (max_level - input - 1);
+                level = descend ? input : (max_level - input);
 
         for (i = 0, j = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
                 /* ignore invalid entry */
@@ -197,7 +199,7 @@ static int get_property(unsigned int cpu, unsigned long input,
 
                 if (property == GET_LEVEL && (unsigned int)input == freq) {
                         /* get level by frequency */
-                        *output = descend ? j : (max_level - j - 1);
+                        *output = descend ? j : (max_level - j);
                         return 0;
                 }
                 if (property == GET_FREQ && level == j) {