diff --git a/arch/arm/src/sama5/sam_udphs.c b/arch/arm/src/sama5/sam_udphs.c
index 501f3cbc939..0ad87e98b42 100644
--- a/arch/arm/src/sama5/sam_udphs.c
+++ b/arch/arm/src/sama5/sam_udphs.c
@@ -3588,32 +3588,36 @@ static int sam_ep_submit(struct usbdev_ep_s *ep, struct usbdev_req_s *req)
   privep->zlpsent   = false;
   flags             = irqsave();
 
-  /* If we are stalled, then drop all requests on the floor */
-
-  if (privep->stalled)
-    {
-      sam_req_abort(privep, privreq, -EBUSY);
-      ulldbg("ERROR: stalled\n");
-      ret = -EBUSY;
-    }
-
   /* Handle IN (device-to-host) requests.  NOTE:  If the class device is
    * using the bi-directional EP0, then we assume that they intend the EP0
-   * IN functionality (EP0 OUT data receipt does not use requests).
+   * IN functionality (EP0 SETUP OUT data receipt does not use requests).
    */
 
-  else if (USB_ISEPIN(ep->eplog) || epno == EP0)
+  if (USB_ISEPIN(ep->eplog) || epno == EP0)
     {
-      /* Add the new request to the request queue for the IN endpoint */
+      /* If the endpoint is stalled, then fail any attempts to write
+       * through the endpoint.
+       */
 
-      sam_req_enqueue(&privep->reqq, privreq);
-      usbtrace(TRACE_INREQQUEUED(epno), req->len);
-
-      /* If the IN endpoint is IDLE, then transfer the data now */
-
-      if (privep->epstate == UDPHS_EPSTATE_IDLE)
+      if (privep->stalled)
         {
-          ret = sam_req_write(priv, privep);
+          sam_req_abort(privep, privreq, -EBUSY);
+          ulldbg("ERROR: stalled\n");
+          ret = -EPERM;
+        }
+      else
+        {
+          /* Add the new request to the request queue for the IN endpoint */
+
+          sam_req_enqueue(&privep->reqq, privreq);
+          usbtrace(TRACE_INREQQUEUED(epno), req->len);
+
+          /* If the IN endpoint is IDLE, then transfer the data now */
+
+          if (privep->epstate == UDPHS_EPSTATE_IDLE)
+            {
+              ret = sam_req_write(priv, privep);
+            }
         }
     }
 
@@ -3750,12 +3754,22 @@ static int sam_ep_stall(struct usbdev_ep_s *ep, bool resume)
         {
           usbtrace(TRACE_EPSTALL, epno);
 
-          /* Abort the current transfer if necessary */
+          /* If this is an IN endpoint (or endpoint 0), then cancel all
+           * of the pending write requests.
+           */
 
-          if (privep->epstate == UDPHS_EPSTATE_SENDING ||
-              privep->epstate == UDPHS_EPSTATE_RECEIVING)
+          if (epno == 0 || USB_ISEPIN(ep->eplog))
             {
-              sam_req_complete(privep, -EIO);
+              sam_req_cancel(privep, -EPERM);
+            }
+
+          /* Otherwise, it is an OUT endpoint.  Complete any read request
+           * currently in progress (it will get requeued immediately).
+           */
+
+          else if (privep->epstate == UDPHS_EPSTATE_RECEIVING)
+            {
+              sam_req_complete(privep, -EPERM);
             }
 
           /* Put endpoint into stalled state */
diff --git a/drivers/usbdev/usbmsc.c b/drivers/usbdev/usbmsc.c
index ee8da5236e6..2faa07b12b8 100644
--- a/drivers/usbdev/usbmsc.c
+++ b/drivers/usbdev/usbmsc.c
@@ -213,6 +213,7 @@ static struct usbdev_req_s *usbmsc_allocreq(FAR struct usbdev_ep_s *ep,
           req = NULL;
         }
     }
+
   return req;
 }
 
@@ -288,6 +289,7 @@ static int usbmsc_bind(FAR struct usbdevclass_driver_s *driver,
       ret = -ENOMEM;
       goto errout;
     }
+
   priv->ctrlreq->callback = usbmsc_ep0incomplete;
 
   /* Pre-allocate all endpoints... the endpoints will not be functional
@@ -306,6 +308,7 @@ static int usbmsc_bind(FAR struct usbdevclass_driver_s *driver,
       ret = -ENODEV;
       goto errout;
     }
+
   priv->epbulkin->priv = priv;
 
   /* Pre-allocate the OUT bulk endpoint */
@@ -317,6 +320,7 @@ static int usbmsc_bind(FAR struct usbdevclass_driver_s *driver,
       ret = -ENODEV;
       goto errout;
     }
+
   priv->epbulkout->priv = priv;
 
   /* Pre-allocate read requests */
@@ -517,7 +521,7 @@ static int usbmsc_setup(FAR struct usbdevclass_driver_s *driver,
     {
       usbtrace(TRACE_CLSERROR(USBMSC_TRACEERR_SETUPINVALIDARGS), 0);
       return -EIO;
-     }
+    }
 #endif
 
   /* Extract reference to private data */
@@ -1070,7 +1074,7 @@ void usbmsc_wrcomplete(FAR struct usbdev_ep_s *ep, FAR struct usbdev_req_s *req)
     {
       usbtrace(TRACE_CLSERROR(USBMSC_TRACEERR_WRCOMPLETEINVALIDARGS), 0);
       return;
-     }
+    }
 #endif
 
   /* Extract references to private data */
@@ -1131,7 +1135,7 @@ void usbmsc_rdcomplete(FAR struct usbdev_ep_s *ep, FAR struct usbdev_req_s *req)
     {
       usbtrace(TRACE_CLSERROR(USBMSC_TRACEERR_RDCOMPLETEINVALIDARGS), 0);
       return;
-     }
+    }
 #endif
 
   /* Extract references to private data */
@@ -1324,6 +1328,7 @@ int usbmsc_configure(unsigned int nluns, void **handle)
       ret = -ENOMEM;
       goto errout;
     }
+
   memset(priv->luntab, 0, priv->nluns * sizeof(struct usbmsc_lun_s));
 
   /* Initialize the USB class driver structure */
@@ -1465,6 +1470,7 @@ int usbmsc_bindlun(FAR void *handle, FAR const char *drvrpath,
           usbtrace(TRACE_CLSERROR(USBMSC_TRACEERR_ALLOCIOBUFFER), geo.geo_sectorsize);
           return -ENOMEM;
         }
+
       priv->iosize = geo.geo_sectorsize;
     }
   else if (priv->iosize < geo.geo_sectorsize)
@@ -1492,6 +1498,7 @@ int usbmsc_bindlun(FAR void *handle, FAR const char *drvrpath,
     {
       lun->readonly = true;
     }
+
   return OK;
 }
 
@@ -1680,6 +1687,7 @@ int usbmsc_classobject(FAR void *handle,
 
       *classdev = &alloc->drvr.drvr;
     }
+
   return ret;
 }
 #endif
@@ -1717,6 +1725,7 @@ void usbmsc_uninitialize(FAR void *handle)
       return;
     }
 #endif
+
   priv = &alloc->dev;
 
   /* If the thread hasn't already exitted, tell it to exit now */
@@ -1735,6 +1744,7 @@ void usbmsc_uninitialize(FAR void *handle)
           pthread_cond_signal(&priv->cond);
           irqrestore(flags);
         }
+
       pthread_mutex_unlock(&priv->mutex);
 
       /* Wait for the thread to exit.  This is necessary even if the
@@ -1744,9 +1754,10 @@ void usbmsc_uninitialize(FAR void *handle)
 
       (void)pthread_join(priv->thread, &value);
     }
+
   priv->thread = 0;
 
-  /* Unregister the driver (unless we are a part of a composite device */
+  /* Unregister the driver (unless we are a part of a composite device) */
 
 #ifndef CONFIG_USBMSC_COMPOSITE
   usbdev_unregister(&alloc->drvr.drvr);
@@ -1758,6 +1769,7 @@ void usbmsc_uninitialize(FAR void *handle)
     {
       usbmsc_lununinitialize(&priv->luntab[i]);
     }
+
   kfree(priv->luntab);
 
   /* Release the I/O buffer */
diff --git a/drivers/usbdev/usbmsc_scsi.c b/drivers/usbdev/usbmsc_scsi.c
index fbeb0f19286..7791141d804 100644
--- a/drivers/usbdev/usbmsc_scsi.c
+++ b/drivers/usbdev/usbmsc_scsi.c
@@ -2619,6 +2619,7 @@ void *usbmsc_workerthread(void *arg)
 
           priv->thstate = USBMSC_STATE_IDLE;
         }
+
       irqrestore(flags);
 
       /* Loop processing each SCSI command state.  Each state handling