From 93d09c31ebcc7622a22b5605b9131e0a7f6f0925 Mon Sep 17 00:00:00 2001
From: hap <happppp@users.noreply.github.com>
Date: Wed, 24 Apr 2024 12:05:38 +0200
Subject: [PATCH] pwm: fix potential time travel issue, hd44102: missing break;

---
 src/devices/video/hd44102.cpp | 1 +
 src/devices/video/hd44102.h   | 2 +-
 src/devices/video/pwm.cpp     | 2 +-
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/devices/video/hd44102.cpp b/src/devices/video/hd44102.cpp
index 49d05f3a797..0f4a617954b 100644
--- a/src/devices/video/hd44102.cpp
+++ b/src/devices/video/hd44102.cpp
@@ -188,6 +188,7 @@ void hd44102_device::control_w(u8 data)
 				m_y = y;
 			}
 		}
+		break;
 	}
 }
 
diff --git a/src/devices/video/hd44102.h b/src/devices/video/hd44102.h
index dfcd8ca0349..1ac813b3dff 100644
--- a/src/devices/video/hd44102.h
+++ b/src/devices/video/hd44102.h
@@ -31,7 +31,7 @@ public:
 	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
diff --git a/src/devices/video/pwm.cpp b/src/devices/video/pwm.cpp
index 7d1ae67c10e..a09c25bb326 100644
--- a/src/devices/video/pwm.cpp
+++ b/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;