From 9d2e179fa565d8af96fb6ce3643e00f999c9210a Mon Sep 17 00:00:00 2001
From: robert-hh <robert@hammelrath.com>
Date: Sat, 22 Oct 2022 21:28:42 +0200
Subject: [PATCH] mimxrt: Fix CPU freeze when calling __WFE() in
 MICROPY_EVENT_POLL_HOOK.

This issue affected i.MX RT 1052, 1062 and 1064.  It seems to be addressed
by Errata ERR006223, which also mentions i.MX RT101x and 102x, but these
devices worked well even without the change.  As a side effect, the current
consumption at an idle REPL drops significantly with this fix.

Fixes issue #7235.
---
 ports/mimxrt/boards/MIMXRT1052_clock_config.c | 1 +
 ports/mimxrt/boards/MIMXRT1062_clock_config.c | 1 +
 ports/mimxrt/boards/MIMXRT1064_clock_config.c | 1 +
 ports/mimxrt/mpconfigport.h                   | 1 +
 4 files changed, 4 insertions(+)

diff --git a/ports/mimxrt/boards/MIMXRT1052_clock_config.c b/ports/mimxrt/boards/MIMXRT1052_clock_config.c
index 934928129..fa7450d48 100644
--- a/ports/mimxrt/boards/MIMXRT1052_clock_config.c
+++ b/ports/mimxrt/boards/MIMXRT1052_clock_config.c
@@ -465,4 +465,5 @@ void BOARD_BootClockRUN(void) {
     IOMUXC_GPR->GPR5 &= ~IOMUXC_GPR_GPR5_VREF_1M_CLK_GPT2_MASK;
     /* Set SystemCoreClock variable. */
     SystemCoreClock = BOARD_BOOTCLOCKRUN_CORE_CLOCK;
+    CLOCK_SetMode(kCLOCK_ModeRun);
 }
diff --git a/ports/mimxrt/boards/MIMXRT1062_clock_config.c b/ports/mimxrt/boards/MIMXRT1062_clock_config.c
index 05474167b..589ffb0b5 100644
--- a/ports/mimxrt/boards/MIMXRT1062_clock_config.c
+++ b/ports/mimxrt/boards/MIMXRT1062_clock_config.c
@@ -487,4 +487,5 @@ void BOARD_BootClockRUN(void) {
     IOMUXC_GPR->GPR5 &= ~IOMUXC_GPR_GPR5_VREF_1M_CLK_GPT2_MASK;
     /* Set SystemCoreClock variable. */
     SystemCoreClock = BOARD_BOOTCLOCKRUN_CORE_CLOCK;
+    CLOCK_SetMode(kCLOCK_ModeRun);
 }
diff --git a/ports/mimxrt/boards/MIMXRT1064_clock_config.c b/ports/mimxrt/boards/MIMXRT1064_clock_config.c
index 5e49a2fff..56dd75d7f 100644
--- a/ports/mimxrt/boards/MIMXRT1064_clock_config.c
+++ b/ports/mimxrt/boards/MIMXRT1064_clock_config.c
@@ -487,4 +487,5 @@ void BOARD_BootClockRUN(void) {
     IOMUXC_GPR->GPR5 &= ~IOMUXC_GPR_GPR5_VREF_1M_CLK_GPT2_MASK;
     /* Set SystemCoreClock variable. */
     SystemCoreClock = BOARD_BOOTCLOCKRUN_CORE_CLOCK;
+    CLOCK_SetMode(kCLOCK_ModeRun);
 }
diff --git a/ports/mimxrt/mpconfigport.h b/ports/mimxrt/mpconfigport.h
index 8642d53ec..3f87800e3 100644
--- a/ports/mimxrt/mpconfigport.h
+++ b/ports/mimxrt/mpconfigport.h
@@ -241,6 +241,7 @@ extern const struct _mp_obj_type_t network_lan_type;
     do { \
         extern void mp_handle_pending(bool); \
         mp_handle_pending(true); \
+        __WFE(); \
     } while (0);
 
 #define MICROPY_MAKE_POINTER_CALLABLE(p) ((void *)((mp_uint_t)(p) | 1))