diff --git a/adb/client/usb_libusb.cpp b/adb/client/usb_libusb.cpp
index 46c3f58..10b6090 100644
--- a/adb/client/usb_libusb.cpp
+++ b/adb/client/usb_libusb.cpp
@@ -589,7 +589,7 @@
 
     int rc = perform_usb_transfer(h, info, std::move(lock));
     LOG(DEBUG) << "usb_write(" << len << ") = " << rc;
-    return rc;
+    return info->transfer->actual_length;
 }
 
 int usb_read(usb_handle* h, void* d, int len) {
diff --git a/adb/client/usb_linux.cpp b/adb/client/usb_linux.cpp
index 1f376a4..aace16d 100644
--- a/adb/client/usb_linux.cpp
+++ b/adb/client/usb_linux.cpp
@@ -418,11 +418,11 @@
     if (h->zero_mask && !(len & h->zero_mask)) {
         // If we need 0-markers and our transfer is an even multiple of the packet size,
         // then send a zero marker.
-        return usb_bulk_write(h, _data, 0);
+        return usb_bulk_write(h, _data, 0) == 0 ? n : -1;
     }
 
     D("-- usb_write --");
-    return 0;
+    return n;
 }
 
 int usb_read(usb_handle *h, void *_data, int len)
diff --git a/adb/client/usb_osx.cpp b/adb/client/usb_osx.cpp
index 8a95a19..49baf36 100644
--- a/adb/client/usb_osx.cpp
+++ b/adb/client/usb_osx.cpp
@@ -497,8 +497,8 @@
         }
     }
 
-    if (0 == result)
-        return 0;
+    if (!result)
+        return len;
 
     LOG(ERROR) << "usb_write failed with status: " << std::hex << result;
     return -1;
diff --git a/adb/client/usb_windows.cpp b/adb/client/usb_windows.cpp
index f529e8f..d2aeb26 100644
--- a/adb/client/usb_windows.cpp
+++ b/adb/client/usb_windows.cpp
@@ -365,7 +365,7 @@
         }
     }
 
-    return 0;
+    return written;
 
 fail:
     // Any failure should cause us to kick the device instead of leaving it a
diff --git a/adb/daemon/usb.cpp b/adb/daemon/usb.cpp
index 8c14955..5242718 100644
--- a/adb/daemon/usb.cpp
+++ b/adb/daemon/usb.cpp
@@ -368,6 +368,7 @@
     D("about to write (fd=%d, len=%d)", h->bulk_in, len);
 
     const char* buf = static_cast<const char*>(data);
+    int orig_len = len;
     while (len > 0) {
         int write_len = std::min(USB_FFS_BULK_SIZE, len);
         int n = adb_write(h->bulk_in, buf, write_len);
@@ -380,13 +381,14 @@
     }
 
     D("[ done fd=%d ]", h->bulk_in);
-    return 0;
+    return orig_len;
 }
 
 static int usb_ffs_read(usb_handle* h, void* data, int len) {
     D("about to read (fd=%d, len=%d)", h->bulk_out, len);
 
     char* buf = static_cast<char*>(data);
+    int orig_len = len;
     while (len > 0) {
         int read_len = std::min(USB_FFS_BULK_SIZE, len);
         int n = adb_read(h->bulk_out, buf, read_len);
@@ -399,7 +401,7 @@
     }
 
     D("[ done fd=%d ]", h->bulk_out);
-    return 0;
+    return orig_len;
 }
 
 static int usb_ffs_do_aio(usb_handle* h, const void* data, int len, bool read) {
@@ -447,6 +449,7 @@
         if (num_bufs == 1 && aiob->events[0].res == -EINTR) {
             continue;
         }
+        int ret = 0;
         for (int i = 0; i < num_bufs; i++) {
             if (aiob->events[i].res < 0) {
                 errno = -aiob->events[i].res;
@@ -454,8 +457,9 @@
                             << " total bufs " << num_bufs;
                 return -1;
             }
+            ret += aiob->events[i].res;
         }
-        return 0;
+        return ret;
     }
 }
 
diff --git a/adb/transport_usb.cpp b/adb/transport_usb.cpp
index 94b2e37..602970c 100644
--- a/adb/transport_usb.cpp
+++ b/adb/transport_usb.cpp
@@ -122,7 +122,7 @@
 // On Android devices, we rely on the kernel to provide buffered read.
 // So we can recover automatically from EOVERFLOW.
 static int remote_read(apacket* p, usb_handle* usb) {
-    if (usb_read(usb, &p->msg, sizeof(amessage))) {
+    if (usb_read(usb, &p->msg, sizeof(amessage)) != sizeof(amessage)) {
         PLOG(ERROR) << "remote usb: read terminated (message)";
         return -1;
     }
@@ -134,7 +134,8 @@
         }
 
         p->payload.resize(p->msg.data_length);
-        if (usb_read(usb, &p->payload[0], p->payload.size())) {
+        if (usb_read(usb, &p->payload[0], p->payload.size())
+                != static_cast<int>(p->payload.size())) {
             PLOG(ERROR) << "remote usb: terminated (data)";
             return -1;
         }
@@ -154,14 +155,14 @@
 }
 
 bool UsbConnection::Write(apacket* packet) {
-    unsigned size = packet->msg.data_length;
+    int size = packet->msg.data_length;
 
-    if (usb_write(handle_, &packet->msg, sizeof(packet->msg)) != 0) {
+    if (usb_write(handle_, &packet->msg, sizeof(packet->msg)) != sizeof(packet->msg)) {
         PLOG(ERROR) << "remote usb: 1 - write terminated";
         return false;
     }
 
-    if (packet->msg.data_length != 0 && usb_write(handle_, packet->payload.data(), size) != 0) {
+    if (packet->msg.data_length != 0 && usb_write(handle_, packet->payload.data(), size) != size) {
         PLOG(ERROR) << "remote usb: 2 - write terminated";
         return false;
     }