power: fix sysfs_read/sysfs_write usage

* The incoming path to sysfs_read/sysfs_write should be const, as in
  open(2) call.
* Redefine scaling_gov_path as const pointer array.
* Since sysfs_read works on a simple absolute path anyway, make sure
  the scaling_gov_path paths *are* absolute.  Otherwise the code only
  works if Power HAL has / as CWD, which is a bit fragile.

Change-Id: I70c08f8137842569514bcb3f6e0617d46044e6ab
Signed-off-by: Corinna Vinschen <xda@vinschen.de>

3 files changed, 12 insertions, 12 deletions

diff --git a/power-8916.c b/power-8916.c
index 3774418..4bf8c0c 100644
--- a/power-8916.c
+++ b/power-8916.c
@@ -51,10 +51,10 @@
 #define MIN_FREQ_CPU0_DISP_OFF 400000
 #define MIN_FREQ_CPU0_DISP_ON 960000
 
-char scaling_min_freq[4][80] = {"sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq",
-                                "sys/devices/system/cpu/cpu1/cpufreq/scaling_min_freq",
-                                "sys/devices/system/cpu/cpu2/cpufreq/scaling_min_freq",
-                                "sys/devices/system/cpu/cpu3/cpufreq/scaling_min_freq"};
+const char* scaling_min_freq[4] = {"/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq",
+                                   "/sys/devices/system/cpu/cpu1/cpufreq/scaling_min_freq",
+                                   "/sys/devices/system/cpu/cpu2/cpufreq/scaling_min_freq",
+                                   "/sys/devices/system/cpu/cpu3/cpufreq/scaling_min_freq"};
 
 static int slack_node_rw_failed = 0;
 
diff --git a/utils.c b/utils.c
index db1637d..ec9d1e8 100644
--- a/utils.c
+++ b/utils.c
@@ -46,10 +46,10 @@
 #define SOC_ID_0 "/sys/devices/soc0/soc_id"
 #define SOC_ID_1 "/sys/devices/system/soc/soc0/id"
 
-char scaling_gov_path[4][80] = {"sys/devices/system/cpu/cpu0/cpufreq/scaling_governor",
-                                "sys/devices/system/cpu/cpu1/cpufreq/scaling_governor",
-                                "sys/devices/system/cpu/cpu2/cpufreq/scaling_governor",
-                                "sys/devices/system/cpu/cpu3/cpufreq/scaling_governor"};
+const char* scaling_gov_path[4] = {"/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor",
+                                   "/sys/devices/system/cpu/cpu1/cpufreq/scaling_governor",
+                                   "/sys/devices/system/cpu/cpu2/cpufreq/scaling_governor",
+                                   "/sys/devices/system/cpu/cpu3/cpufreq/scaling_governor"};
 
 #define PERF_HAL_PATH "libqti-perfd-client.so"
 static void* qcopt_handle;
@@ -117,7 +117,7 @@ static void __attribute__((destructor)) cleanup(void) {
     }
 }
 
-int sysfs_read(char* path, char* s, int num_bytes) {
+int sysfs_read(const char* path, char* s, int num_bytes) {
     char buf[80];
     int count;
     int ret = 0;
@@ -144,7 +144,7 @@ int sysfs_read(char* path, char* s, int num_bytes) {
     return ret;
 }
 
-int sysfs_write(char* path, char* s) {
+int sysfs_write(const char* path, char* s) {
     char buf[80];
     int len;
     int ret = 0;
diff --git a/utils.h b/utils.h
index 2d45e72..e5748dc 100644
--- a/utils.h
+++ b/utils.h
@@ -29,8 +29,8 @@
 
 #include <cutils/properties.h>
 
-int sysfs_read(char* path, char* s, int num_bytes);
-int sysfs_write(char* path, char* s);
+int sysfs_read(const char* path, char* s, int num_bytes);
+int sysfs_write(const char* path, char* s);
 int get_scaling_governor(char governor[], int size);
 int get_scaling_governor_check_cores(char governor[], int size, int core_num);
 int is_interactive_governor(char*);