Merge "adbd: Don't close/reopen FFS ep0 on disconnect"

Author: Linux Build Service Account

adb/usb_linux_client.c

@@ -313,23 +313,25 @@ static void init_functionfs(struct usb_handle *h)
 {
     ssize_t ret;
 
-    D("OPENING %s\n", USB_FFS_ADB_EP0);
-    h->control = adb_open(USB_FFS_ADB_EP0, O_RDWR);
-    if (h->control < 0) {
-        D("[ %s: cannot open control endpoint: errno=%d]\n", USB_FFS_ADB_EP0, errno);
-        goto err;
-    }
+    if (h->control < 0) { // might have already done this before
+        D("OPENING %s\n", USB_FFS_ADB_EP0);
+        h->control = adb_open(USB_FFS_ADB_EP0, O_RDWR);
+        if (h->control < 0) {
+            D("[ %s: cannot open control endpoint: errno=%d]\n", USB_FFS_ADB_EP0, errno);
+            goto err;
+        }
 
-    ret = adb_write(h->control, &descriptors, sizeof(descriptors));
-    if (ret < 0) {
-        D("[ %s: write descriptors failed: errno=%d ]\n", USB_FFS_ADB_EP0, errno);
-        goto err;
-    }
+        ret = adb_write(h->control, &descriptors, sizeof(descriptors));
+        if (ret < 0) {
+            D("[ %s: write descriptors failed: errno=%d ]\n", USB_FFS_ADB_EP0, errno);
+            goto err;
+        }
 
-    ret = adb_write(h->control, &strings, sizeof(strings));
-    if (ret < 0) {
-        D("[ %s: writing strings failed: errno=%d]\n", USB_FFS_ADB_EP0, errno);
-        goto err;
+        ret = adb_write(h->control, &strings, sizeof(strings));
+        if (ret < 0) {
+            D("[ %s: writing strings failed: errno=%d]\n", USB_FFS_ADB_EP0, errno);
+            goto err;
+        }
     }
 
     h->bulk_out = adb_open(USB_FFS_ADB_OUT, O_RDWR);
@@ -369,14 +371,14 @@ static void *usb_ffs_open_thread(void *x)
     while (1) {
         // wait until the USB device needs opening
         adb_mutex_lock(&usb->lock);
-        while (usb->control != -1)
+        while (usb->control != -1 && usb->bulk_in != -1 && usb->bulk_out != -1)
             adb_cond_wait(&usb->notify, &usb->lock);
         adb_mutex_unlock(&usb->lock);
 
         while (1) {
             init_functionfs(usb);
 
-            if (usb->control >= 0)
+            if (usb->control >= 0 && usb->bulk_in >= 0 && usb->bulk_out >= 0)
                 break;
 
             adb_sleep_ms(1000);
@@ -473,10 +475,13 @@ static void usb_ffs_kick(usb_handle *h)
         D("[ kick: sink (fd=%d) clear halt failed (%d) ]", h->bulk_out, errno);
 
     adb_mutex_lock(&h->lock);
-    adb_close(h->control);
+
+    // don't close ep0 here, since we may not need to reinitialize it with
+    // the same descriptors again. if however ep1/ep2 fail to re-open in
+    // init_functionfs, only then would we close and open ep0 again.
     adb_close(h->bulk_out);
     adb_close(h->bulk_in);
-    h->control = h->bulk_out = h->bulk_in = -1;
+    h->bulk_out = h->bulk_in = -1;
 
     // notify usb_ffs_open_thread that we are disconnected
     adb_cond_signal(&h->notify);