From 38fe9bcdf8f2c4334bec983f6f04f19e9cff6339 Mon Sep 17 00:00:00 2001
From: Gerardo Rodriguez <gerardo.espinoza@nxp.com>
Date: Wed, 7 Oct 2020 17:53:03 -0500
Subject: [PATCH] #64 Assume "PC connected" at the start of USB communication
 instead of waiting for the whole enumeration process to be finished.

---
 source/board/microbitv2/microbitv2.c | 10 +++++++---
 source/usb/usb_lib.c                 |  3 +++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/source/board/microbitv2/microbitv2.c b/source/board/microbitv2/microbitv2.c
index a55b049d6..7b5e9c108 100644
--- a/source/board/microbitv2/microbitv2.c
+++ b/source/board/microbitv2/microbitv2.c
@@ -336,9 +336,6 @@ void board_30ms_hook()
   static uint8_t blink_in_progress = 0;
     
     if (usb_state == USB_CONNECTED) {
-        /* Set usb_pc_connected to true to prevent entering sleep mode when host does re-enumeration.
-        *  Will be set to false when the USB cable is detached. */
-        usb_pc_connected = true;
         // configure pin as GPIO
         PIN_HID_LED_PORT->PCR[PIN_HID_LED_BIT] = PORT_PCR_MUX(1);
         power_led_max_duty_cycle = PWR_LED_ON_MAX_BRIGHTNESS;
@@ -508,6 +505,13 @@ void board_handle_powerdown()
     }
 }
 
+void board_usb_sof_event(void)
+{
+    /* Set usb_pc_connected to true to prevent entering sleep mode when host does re-enumeration.
+    *  Will be set to false when the USB cable is detached. */
+    usb_pc_connected = true;
+}
+
 void vfs_user_build_filesystem_hook() {
     uint32_t file_size;
     error_t status;
diff --git a/source/usb/usb_lib.c b/source/usb/usb_lib.c
index ca177d9f2..dfd9e4b10 100644
--- a/source/usb/usb_lib.c
+++ b/source/usb/usb_lib.c
@@ -1065,6 +1065,8 @@ void USBD_Reset_Event(void)
 #endif
 #endif  /* ((USBD_CDC_ACM_ENABLE)) */
 
+__weak void board_usb_sof_event(void) {}
+
 #if   ((USBD_HID_ENABLE) || (USBD_ADC_ENABLE) || (USBD_CDC_ACM_ENABLE) || (USBD_CLS_ENABLE))
 #ifndef __RTX
 void USBD_SOF_Event(void)
@@ -1081,6 +1083,7 @@ void USBD_SOF_Event(void)
 #if    (USBD_CLS_ENABLE)
     USBD_CLS_SOF_Event();
 #endif
+    board_usb_sof_event();
 }
 #endif
 #endif  /* ((USBD_HID_ENABLE) || (USBD_ADC_ENABLE) || (USBD_CDC_ACM_ENABLE) || (USBD_CLS_ENABLE)) */