pwm: fix potential time travel issue, hd44102: missing break;

Author: happppp

src/devices/video/hd44102.cpp

@@ -188,6 +188,7 @@ void hd44102_device::control_w(u8 data)
 				m_y = y;
 			}
 		}
+		break;
 	}
 }
 

src/devices/video/hd44102.h

@@ -31,7 +31,7 @@ class hd44102_device : public device_t
 	void write(offs_t offset, u8 data);
 
 	const u8 *render();
-	u32 screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
+	u32 screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect); // optional
 
 protected:
 	// device-level overrides

src/devices/video/pwm.cpp

@@ -274,11 +274,11 @@ void pwm_display_device::sync()
 {
 	const attotime now = machine().time();
 	const attotime last = m_sync_time;
-	m_sync_time = now;
 
 	if (last >= now)
 		return;
 
+	m_sync_time = now;
 	const attotime diff = now - last;
 	u64 sel = m_rowsel;