The "clock_set_mul_div" function doesn't propagate the clock period to
the children if it is changed (e.g. by enabling/disabling
a clock multiplexer).
This was overlooked during the implementation due to late changes.

This commit propagates the change if the multiplier or divider changes.

The usart tests will ensure that this behavior will not regress.

Signed-off-by: Arnaud Minier <arnaud.minier@telecom-paris.fr>
Signed-off-by: Inès Varhol <ines.varhol@telecom-paris.fr>
---
 hw/misc/stm32l4x5_rcc.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/misc/stm32l4x5_rcc.c b/hw/misc/stm32l4x5_rcc.c
index bc2d63528b..4725ba4f1c 100644
--- a/hw/misc/stm32l4x5_rcc.c
+++ b/hw/misc/stm32l4x5_rcc.c
@@ -59,7 +59,12 @@ static void clock_mux_update(RccClockMuxState *mux, bool bypass_source)
         freq_multiplier = mux->divider;
     }
 
-    clock_set_mul_div(mux->out, freq_multiplier, mux->multiplier);
+    if ((mux->out->multiplier != freq_multiplier) ||
+        mux->out->divider != mux->multiplier) {
+        clock_set_mul_div(mux->out, freq_multiplier, mux->multiplier);
+        clock_propagate(mux->out);
+    }
+
     clock_update(mux->out, clock_get(current_source));
 
     src_freq = clock_get_hz(current_source);
-- 
2.34.1