[PULL,04/35] hw/clock: Only propagate clock changes if the clock is changed

Commit Message

Peter Maydell Aug. 28, 2020, 9:23 a.m. UTC

From: Philippe Mathieu-Daudé <[e-mail]>

Avoid propagating the clock change when the clock does not change.

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
Reviewed-by: Richard Henderson <[e-mail]>
Message-id: [e-mail]
Signed-off-by: Peter Maydell <[e-mail]>
---
 include/hw/clock.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Patch

diff --git a/include/hw/clock.h b/include/hw/clock.h
index d85af45c967..9ecd78b2c30 100644
--- a/include/hw/clock.h
+++ b/include/hw/clock.h
@@ -165,8 +165,9 @@  void clock_propagate(Clock *clk);
  */
 static inline void clock_update(Clock *clk, uint64_t value)
 {
-    clock_set(clk, value);
-    clock_propagate(clk);
+    if (clock_set(clk, value)) {
+        clock_propagate(clk);
+    }
 }
 
 static inline void clock_update_hz(Clock *clk, unsigned hz)