drivers/timer/arm_arch_timer: Fix cycles overflow with GDB stub

drivers/timer/arm_arch_timer.c

@@ -20,6 +20,14 @@ static uint32_t cyc_per_tick;
 				/ CONFIG_SYS_CLOCK_TICKS_PER_SEC)
 #endif
 
+#if defined(CONFIG_GDBSTUB)
+/* When interactively debugging, the cycle diff can overflow 32-bit variable */
+#define TO_CYCLE_DIFF(x) (x)
+#else
+/* Convert to 32-bit for fast division */
+#define TO_CYCLE_DIFF(x) ((cycle_diff_t)(x))
+#endif
+
 /* the unsigned long cast limits divisors to native CPU register width */
 #define cycle_diff_t unsigned long
 
@@ -58,7 +66,7 @@ static void arm_arch_timer_compare_isr(const void *arg)
 
 	uint64_t curr_cycle = arm_arch_timer_count();
 	uint64_t delta_cycles = curr_cycle - last_cycle;
-	uint32_t delta_ticks = (cycle_diff_t)delta_cycles / CYC_PER_TICK;
+	uint32_t delta_ticks = TO_CYCLE_DIFF(delta_cycles) / CYC_PER_TICK;
 
 	last_cycle += (cycle_diff_t)delta_ticks * CYC_PER_TICK;
 	last_tick += delta_ticks;