From 07708f15185d96930621493c3e2886cc2e948622 Mon Sep 17 00:00:00 2001
From: Gadi Rotenberg <gadi@polynero.com>
Date: Sun, 9 Feb 2020 13:25:16 +0200
Subject: [PATCH] Added fix to allow remount when usb enabled but msc is
 ejected

---
 shared-module/storage/__init__.c      |  4 +---
 supervisor/shared/usb/usb_msc_flash.c | 10 +++++++++-
 supervisor/usb.h                      |  1 +
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/shared-module/storage/__init__.c b/shared-module/storage/__init__.c
index 215e1356a3..c3d4b50c8e 100644
--- a/shared-module/storage/__init__.c
+++ b/shared-module/storage/__init__.c
@@ -149,9 +149,7 @@ void common_hal_storage_remount(const char *mount_path, bool readonly, bool disa
     }
 
     #ifdef USB_AVAILABLE
-    // TODO(dhalbert): is this is a good enough check? It checks for
-    // CDC enabled. There is no "MSC enabled" check.
-    if (usb_enabled()) {
+    if (!usb_msc_ejected()) {
         mp_raise_RuntimeError(translate("Cannot remount '/' when USB is active."));
     }
     #endif
diff --git a/supervisor/shared/usb/usb_msc_flash.c b/supervisor/shared/usb/usb_msc_flash.c
index 0376cfc1df..c0279f9e5f 100644
--- a/supervisor/shared/usb/usb_msc_flash.c
+++ b/supervisor/shared/usb/usb_msc_flash.c
@@ -39,7 +39,7 @@
 
 #define MSC_FLASH_BLOCK_SIZE    512
 
-static bool ejected[1];
+static bool ejected[1] = {true};
 
 void usb_msc_mount(void) {
     // Reset the ejection tracking every time we're plugged into USB. This allows for us to battery
@@ -53,6 +53,14 @@ void usb_msc_umount(void) {
 
 }
 
+bool usb_msc_ejected(void) {
+    bool all_ejected = true;
+    for (uint8_t i = 0; i < sizeof(ejected); i++) {
+        all_ejected &= ejected[i];
+    }
+    return all_ejected;
+}
+
 // The root FS is always at the end of the list.
 static fs_user_mount_t* get_vfs(int lun) {
     // TODO(tannewt): Return the mount which matches the lun where 0 is the end
diff --git a/supervisor/usb.h b/supervisor/usb.h
index 0cc361619d..29280c725b 100644
--- a/supervisor/usb.h
+++ b/supervisor/usb.h
@@ -44,5 +44,6 @@ void usb_init(void);
 // Propagate plug/unplug events to the MSC logic.
 void usb_msc_mount(void);
 void usb_msc_umount(void);
+bool usb_msc_ejected(void);
 
 #endif // MICROPY_INCLUDED_SUPERVISOR_USB_H