compositor: Make backlight_current int32_t to avoid unsigned overflow
Backlight brightness was wrapping around when decrementing from 0.
diff --git a/src/compositor.h b/src/compositor.h
index 06476cc..a4292d2 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -197,7 +197,7 @@
int (*switch_mode)(struct weston_output *output, struct weston_mode *mode);
/* backlight values are on 0-255 range, where higher is brighter */
- uint32_t backlight_current;
+ int32_t backlight_current;
void (*set_backlight)(struct weston_output *output, uint32_t value);
void (*set_dpms)(struct weston_output *output, enum dpms_enum level);