From 18bdda9a377cae97648558254efd11d03447be3d Mon Sep 17 00:00:00 2001
From: Dan Walkes <danwalkes@trellis-logic.com>
Date: Thu, 2 Feb 2017 22:34:00 -0700
Subject: [PATCH] Mark position after execute for CRC retry

I've noticed when using in a noisy environment if I ever see a CRC error
all of the subsequent retries fail and the download fails.

I noticed if I print the CRC values expected they change on each retry
attempt.  This seems wrong, since I believe the intent is just to re-send
the last chunk.

I suspect there's a mark() call missing in the success transfer case,
and the position of the last successful create->execute transfer should
be saved. The next retry transfer should only reset to this mark position
and not the beginning of the file.

If I add a call to mFirwmareStream.mark in the CRC success case after
writeExecute() completes I am able to successfully recover from CRC errors.
---
 .../main/java/no/nordicsemi/android/dfu/SecureDfuImpl.java | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/dfu/src/main/java/no/nordicsemi/android/dfu/SecureDfuImpl.java b/dfu/src/main/java/no/nordicsemi/android/dfu/SecureDfuImpl.java
index 43f49e6..cf27c69 100644
--- a/dfu/src/main/java/no/nordicsemi/android/dfu/SecureDfuImpl.java
+++ b/dfu/src/main/java/no/nordicsemi/android/dfu/SecureDfuImpl.java
@@ -514,13 +514,16 @@ import no.nordicsemi.android.error.SecureDfuError;
 					// Increment iterator
 					currentChunk++;
 					attempt = 1;
+					mFirmwareStream.mark(0);
 				} else {
 					if (attempt < MAX_ATTEMPTS) {
 						attempt++;
-						logi("CRC does not match! Retrying...(" + attempt + "/" + MAX_ATTEMPTS + ")");
+						logi(String.format(Locale.US,"CRC does not match! Expected %08X Retrying...(%d/%d)",crc,attempt,MAX_ATTEMPTS));
 						mService.sendLogBroadcast(DfuBaseService.LOG_LEVEL_WARNING, "CRC does not match! Retrying...(" + attempt + "/" + MAX_ATTEMPTS + ")");
 						try {
 							mFirmwareStream.reset();
+							final int crcAfterReset = (int) (((ArchiveInputStream) mFirmwareStream).getCrc32() & 0xFFFFFFFFL);
+							logi(String.format(Locale.US,"CRC after reset is %08X",crcAfterReset));
 							mProgressInfo.setBytesSent(checksum.offset - info.maxSize);
 						} catch (final IOException e) {
 							loge("Error while resetting the firmware stream", e);
@@ -528,7 +531,7 @@ import no.nordicsemi.android.error.SecureDfuError;
 							return;
 						}
 					} else {
-						loge("CRC does not match!");
+						loge(String.format("CRC does not match! Expected %08X",crc));
 						mService.sendLogBroadcast(DfuBaseService.LOG_LEVEL_ERROR, "CRC does not match!");
 						mService.terminateConnection(gatt, DfuBaseService.ERROR_CRC_ERROR);
 						return;