From 816053ba7c4ae766fa9d44f88f48f726ca372307 Mon Sep 17 00:00:00 2001
From: David Lechner <david@pybricks.com>
Date: Tue, 19 Jan 2021 11:35:25 -0600
Subject: [PATCH] don't expect response on disconnect commands

The LWP3 bootloader disconnect and reboot commands cause the device
to disconnect before sending a response, so we must always use
write without response for these, otherwise the program can hang
waiting for a response.
---
 src/sagas/lwp3-bootloader-protocol.test.ts | 7 ++++++-
 src/sagas/lwp3-bootloader-protocol.ts      | 4 ++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/sagas/lwp3-bootloader-protocol.test.ts b/src/sagas/lwp3-bootloader-protocol.test.ts
index b79d4839..8e59a032 100644
--- a/src/sagas/lwp3-bootloader-protocol.test.ts
+++ b/src/sagas/lwp3-bootloader-protocol.test.ts
@@ -121,6 +121,11 @@ describe('message encoder', () => {
             ],
         ],
     ])('encode %s request', async (_n, request, expected) => {
+        const messageTypesThatShouldBeCalledWithoutResponse = [
+            BootloaderRequestActionType.Program,
+            BootloaderRequestActionType.Reboot,
+            BootloaderRequestActionType.Disconnect,
+        ];
         const saga = new AsyncSaga(bootloader);
         saga.put(request);
         const message = new Uint8Array(expected);
@@ -128,7 +133,7 @@ describe('message encoder', () => {
         expect(action).toEqual(
             send(
                 message,
-                /* withResponse */ request.type !== BootloaderRequestActionType.Program,
+                !messageTypesThatShouldBeCalledWithoutResponse.includes(request.type),
             ),
         );
         await saga.end();
diff --git a/src/sagas/lwp3-bootloader-protocol.ts b/src/sagas/lwp3-bootloader-protocol.ts
index 8cc4cc33..e60f5422 100644
--- a/src/sagas/lwp3-bootloader-protocol.ts
+++ b/src/sagas/lwp3-bootloader-protocol.ts
@@ -81,7 +81,7 @@ function* encodeRequest(): Generator {
                 );
                 break;
             case BootloaderRequestActionType.Reboot:
-                yield put(send(createStartAppRequest()));
+                yield put(send(createStartAppRequest(), /* withResponse */ false));
                 break;
             case BootloaderRequestActionType.Init:
                 yield put(send(createInitLoaderRequest(action.firmwareSize)));
@@ -96,7 +96,7 @@ function* encodeRequest(): Generator {
                 yield put(send(createGetFlashStateRequest()));
                 break;
             case BootloaderRequestActionType.Disconnect:
-                yield put(send(createDisconnectRequest()));
+                yield put(send(createDisconnectRequest(), /* withResponse */ false));
                 break;
             /* istanbul ignore next: should not be possible to reach */
             default: