commit f7454622eaac287d20ab43013d7015fe42b894f8
author Mike Lockwood <lockwood@android.com> Thu Dec 09 18:34:18 2010 -0800
committer Mike Lockwood <lockwood@android.com> Thu Dec 09 18:34:18 2010 -0800
tree 1bbc63dbaf849ed5226194e933f2de3c9bdb22e0
parent 424c6cbfa75da5f4f889ab6517dfee4dd024ba2d

MTP host: Handle receiving a response packet instead of data packet.

This will happen if the device needs to report an error rather than returning the data.

Change-Id: I477512b3676c2f0518a85a4135832ed4475fbc2d
Signed-off-by: Mike Lockwood <lockwood@android.com>

media/mtp/MtpDevice.cpp

diff --git a/media/mtp/MtpDevice.cpp b/media/mtp/MtpDevice.cpp
index 8ad39dc..e058a5a 100644
--- a/media/mtp/MtpDevice.cpp
+++ b/media/mtp/MtpDevice.cpp
@@ -49,7 +49,8 @@
         mDeviceInfo(NULL),
         mID(usb_device_get_unique_id(device)),
         mSessionID(0),
-        mTransactionID(0)
+        mTransactionID(0),
+        mReceivedResponse(false)
 {
 }
 
@@ -513,6 +514,7 @@
 
 bool MtpDevice::sendRequest(MtpOperationCode operation) {
     LOGV("sendRequest: %s\n", MtpDebug::getOperationCodeName(operation));
+    mReceivedResponse = false;
     mRequest.setOperationCode(operation);
     if (mTransactionID > 0)
         mRequest.setTransactionID(mTransactionID++);
@@ -535,6 +537,14 @@
     int ret = mData.read(mEndpointIn);
     LOGV("readData returned %d\n", ret);
     if (ret >= MTP_CONTAINER_HEADER_SIZE) {
+        if (mData.getContainerType() == MTP_CONTAINER_TYPE_RESPONSE) {
+            LOGD("got response packet instead of data packet");
+            // we got a response packet rather than data
+            // copy it to mResponse
+            mResponse.copyFrom(mData);
+            mReceivedResponse = true;
+            return false;
+        }
         mData.dump();
         return true;
     }
@@ -552,12 +562,15 @@
 
 MtpResponseCode MtpDevice::readResponse() {
     LOGV("readResponse\n");
+    if (mReceivedResponse) {
+        mReceivedResponse = false;
+        return mResponse.getResponseCode();
+    }
     int ret = mResponse.read(mEndpointIn);
     if (ret >= MTP_CONTAINER_HEADER_SIZE) {
         mResponse.dump();
         return mResponse.getResponseCode();
-    }
-    else {
+    } else {
         LOGD("readResponse failed\n");
         return -1;
     }