Fix reversal of "always/never" in "LCD setting > Sleep (After Backlight Off)"

The bug was introduced in a06d9c8.
The patch also fixes some (more or less) related obsolete comments.

Change-Id: I5e491d64574c37cdbc46b146d7cfc555d86b9a11

2 files changed, 14 insertions, 11 deletions

diff --git a/apps/settings.h b/apps/settings.h
index ee67a1734f..fc82c8bf45 100644
--- a/apps/settings.h
+++ b/apps/settings.h
@@ -668,9 +668,8 @@ struct user_settings
 #endif
     unsigned char kbd_file[MAX_FILENAME+1];  /* last keyboard */
 #endif /* HAVE_LCD_BITMAP */
-    int  backlight_timeout;  /* backlight off timeout:  0-18 0=never,
-                               1=always,
-                               then according to timeout_values[] */
+    int  backlight_timeout;  /* backlight off timeout:  -1=never,
+                                0=always, or time in seconds */
     bool caption_backlight; /* turn on backlight at end and start of track */
     bool bl_filter_first_keypress;   /* filter first keypress when dark? */
 #if CONFIG_CHARGING
@@ -689,7 +688,8 @@ struct user_settings
 #endif
 #ifdef HAVE_LCD_SLEEP_SETTING
     int lcd_sleep_after_backlight_off; /* when to put lcd to sleep after backlight
-                                          has turned off */
+                                          has turned off:  -1=never, 0=always,
+                                          or time in seconds */
 #endif
 #endif /* HAVE_BACKLIGHT */
 
@@ -707,8 +707,8 @@ struct user_settings
 #ifdef HAVE_REMOTE_LCD
     /* remote lcd */
     int  remote_contrast;          /* lcd contrast:       0-63 0=low 63=high */
-    int  remote_backlight_timeout; /* backlight off timeout:  0-18 0=never,
-                                   1=always, then according to timeout_values[] */
+    int  remote_backlight_timeout; /* backlight off timeout:  -1=never,
+                                      0=always, or time in seconds */
     int  remote_backlight_timeout_plugged;
     int  remote_scroll_speed;      /* long texts scrolling speed: 1-30 */
     int  remote_scroll_delay;      /* delay (in 1/10s) before starting scroll */
diff --git a/firmware/backlight.c b/firmware/backlight.c
index caff55ce5e..e8a71af12c 100644
--- a/firmware/backlight.c
+++ b/firmware/backlight.c
@@ -209,15 +209,18 @@ static void backlight_lcd_sleep_countdown(bool start)
     }
 
     /* Start LCD sleep countdown */
-    if (lcd_sleep_timeout < 0)
+    if (lcd_sleep_timeout <= 0)
     {
-        lcd_sleep_timer = 0; /* Setting == Always */
-        /* Ensure lcd_sleep() is called from backlight_thread() */
+        lcd_sleep_timer = 0;
+        if (lcd_sleep_timeout == 0) /* Setting == Always */
+        {
+            /* Ensure lcd_sleep() is called from backlight_thread() */
 #if (CONFIG_BACKLIGHT_FADING == BACKLIGHT_FADING_PWM)
-        queue_post(&backlight_queue, LCD_SLEEP, 0);
+            queue_post(&backlight_queue, LCD_SLEEP, 0);
 #else
-        lcd_sleep();
+            lcd_sleep();
 #endif
+        }
     }
     else
     {