backlight: split out read_saved_brightness()

No functional change, just refactoring.

1 files changed, 40 insertions, 26 deletions

diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
index c988a7bd14..4298654479 100644
--- a/src/backlight/backlight.c
+++ b/src/backlight/backlight.c
@@ -510,6 +510,37 @@ static int build_save_file_path(sd_device *device, char **ret) {
         return 0;
 }
 
+static int read_saved_brightness(sd_device *device, unsigned *ret) {
+        _cleanup_free_ char *path = NULL, *value = NULL;
+        int r;
+
+        assert(device);
+        assert(ret);
+
+        r = build_save_file_path(device, &path);
+        if (r < 0)
+                return r;
+
+        r = read_one_line_file(path, &value);
+        if (r < 0) {
+                if (r != -ENOENT)
+                        log_device_error_errno(device, r, "Failed to read %s: %m", path);
+                return r;
+        }
+
+        r = safe_atou(value, ret);
+        if (r < 0) {
+                log_device_warning_errno(device, r,
+                                         "Failed to parse saved brightness '%s', removing %s.",
+                                         value, path);
+                (void) unlink(path);
+                return r;
+        }
+
+        log_device_debug(device, "Using saved brightness %u.", *ret);
+        return 0;
+}
+
 static int device_new_from_arg(const char *s, sd_device **ret) {
         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
         _cleanup_free_ char *subsystem = NULL;
@@ -552,7 +583,6 @@ static int device_new_from_arg(const char *s, sd_device **ret) {
 
 static int run(int argc, char *argv[]) {
         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
-        _cleanup_free_ char *saved = NULL;
         unsigned max_brightness, brightness;
         int r;
 
@@ -581,10 +611,6 @@ static int run(int argc, char *argv[]) {
         if (r <= 0)
                 return r;
 
-        r = build_save_file_path(device, &saved);
-        if (r < 0)
-                return r;
-
         /* If there are multiple conflicting backlight devices, then their probing at boot-time might
          * happen in any order. This means the validity checking of the device then is not reliable,
          * since it might not see other devices conflicting with a specific backlight. To deal with
@@ -592,7 +618,6 @@ static int run(int argc, char *argv[]) {
          * be complete), so that the validity check at boot time doesn't have to be reliable. */
 
         if (streq(argv[1], "load")) {
-                _cleanup_free_ char *value = NULL;
                 unsigned percent;
                 bool clamp;
 
@@ -604,25 +629,7 @@ static int run(int argc, char *argv[]) {
 
                 clamp = shall_clamp(device, &percent);
 
-                r = read_one_line_file(saved, &value);
-                if (r < 0 && r != -ENOENT)
-                        return log_error_errno(r, "Failed to read %s: %m", saved);
-                if (r > 0) {
-                        r = safe_atou(value, &brightness);
-                        if (r < 0) {
-                                log_warning_errno(r, "Failed to parse saved brightness '%s', removing %s.",
-                                                  value, saved);
-                                (void) unlink(saved);
-                        } else {
-                                log_debug("Using saved brightness %u.", brightness);
-                                if (clamp)
-                                        (void) clamp_brightness(device, percent, /* saved = */ true, max_brightness, &brightness);
-
-                                /* Do not fall back to read current brightness below. */
-                                r = 1;
-                        }
-                }
-                if (r <= 0) {
+                if (read_saved_brightness(device, &brightness) < 0) {
                         /* Fallback to clamping current brightness or exit early if clamping is not
                          * supported/enabled. */
                         if (!clamp)
@@ -633,13 +640,20 @@ static int run(int argc, char *argv[]) {
                                 return log_device_error_errno(device, r, "Failed to read current brightness: %m");
 
                         (void) clamp_brightness(device, percent, /* saved = */ false, max_brightness, &brightness);
-                }
+                } else if (clamp)
+                        (void) clamp_brightness(device, percent, /* saved = */ true, max_brightness, &brightness);
 
                 r = sd_device_set_sysattr_valuef(device, "brightness", "%u", brightness);
                 if (r < 0)
                         return log_device_error_errno(device, r, "Failed to write system 'brightness' attribute: %m");
 
         } else if (streq(argv[1], "save")) {
+                _cleanup_free_ char *saved = NULL;
+
+                r = build_save_file_path(device, &saved);
+                if (r < 0)
+                        return r;
+
                 if (validate_device(device) == 0) {
                         (void) unlink(saved);
                         return 0;