Add baseline_patch/patches/baseline_recalc_on_switch.patch

baseline_patch/patches/baseline_recalc_on_switch.patch

@@ -0,0 +1,36 @@
+diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
+index 1a2b3c4d5e6f..7f6e5d4c3b2a 100644
+--- a/kernel/time/clocksource.c
++++ b/kernel/time/clocksource.c
+@@
+ struct clocksource *curr_clocksource;
+ 
+ static bool baseline_recalc_on_switch(struct clocksource *cs);
+ 
+ static void clocksource_select(void)
+ {
+@@
+-	clock->read(clock);
++	/*
++	 * Guarantee a fresh baseline so the first read() after a
++	 * clocksource switch does not inherit stale offsets.
++	 */
++	if (clock->rebaseline && baseline_recalc_on_switch(clock))
++		clock->rebaseline = false;
++
++	clock->read(clock);
+ }
+ 
+ static bool baseline_recalc_on_switch(struct clocksource *cs)
+ {
+-	return false;
++	u64 now;
++
++	if (!cs || !cs->read)
++		return false;
++
++	now = cs->read(cs);
++	cs->switch_time = now;
++
++	return true;
+ }