usb: chipidea: udc: improve error handling on _hardware_enqueue

_hardware_enqueue() didn't check for errors when using
add_td_to_list() which can fail if dma_pool_alloc fails, thus
causing a kernel panic when lastnode->ptr is NULL.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index d917b3f..b1e7b71 100644 (file)
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -434,19 +434,28 @@ static int _hardware_enqueue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
        if (hwreq->req.dma % PAGE_SIZE)
                pages--;
 
-       if (rest == 0)
-               add_td_to_list(hwep, hwreq, 0);
+       if (rest == 0) {
+               ret = add_td_to_list(hwep, hwreq, 0);
+               if (ret < 0)
+                       goto done;
+       }
 
        while (rest > 0) {
                unsigned count = min(hwreq->req.length - hwreq->req.actual,
                                        (unsigned)(pages * CI_HDRC_PAGE_SIZE));
-               add_td_to_list(hwep, hwreq, count);
+               ret = add_td_to_list(hwep, hwreq, count);
+               if (ret < 0)
+                       goto done;
+
                rest -= count;
        }
 
        if (hwreq->req.zero && hwreq->req.length && hwep->dir == TX
-           && (hwreq->req.length % hwep->ep.maxpacket == 0))
-               add_td_to_list(hwep, hwreq, 0);
+           && (hwreq->req.length % hwep->ep.maxpacket == 0)) {
+               ret = add_td_to_list(hwep, hwreq, 0);
+               if (ret < 0)
+                       goto done;
+       }
 
        firstnode = list_first_entry(&hwreq->tds, struct td_node, td);