esp8266/esp_mphal: Add tentative change to mp_hal_stdin_rx_chr() to wait IRQ.

Instead of busy-looping waiting for UART input. Not enabled by default,
needs more testing.

1 files changed, 7 insertions, 0 deletions

diff --git a/esp8266/esp_mphal.c b/esp8266/esp_mphal.c
index dc6944fd4..7c9590ab6 100644
--- a/esp8266/esp_mphal.c
+++ b/esp8266/esp_mphal.c
@@ -60,7 +60,14 @@ int mp_hal_stdin_rx_chr(void) {
         if (c != -1) {
             return c;
         }
+        #if 0
+        // Idles CPU but need more testing before enabling
+        if (!ets_loop_iter()) {
+            asm("waiti 0");
+        }
+        #else
         mp_hal_delay_us(1);
+        #endif
     }
 }