kern: wait 100us after synchronizing cores before saving interrupt state on sleep

libraries/libmesosphere/source/board/nintendo/nx/kern_k_sleep_manager.cpp

@@ -524,6 +524,14 @@ namespace ams::kern::board::nintendo::nx {
                 /* Ensure that all cores get to this point before continuing. */
                 cpu::SynchronizeAllCores();
 
+                /* Wait 100us before continuing. */
+                {
+                    const s64 timeout = KHardwareTimer::GetTick() + ams::svc::Tick(TimeSpan::FromMicroSeconds(100));
+                    while (KHardwareTimer::GetTick() < timeout) {
+                        __asm__ __volatile__("" ::: "memory");
+                    }
+                }
+
                 /* Save the interrupt manager's state. */
                 Kernel::GetInterruptManager().Save(core_id);