usb/hcd: Ensure scatter-gather is not used for isoc transfers

We don't support sg for isoc transfers, enforce this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 190b1ec7bdcbba1d3881421cd91b1195fea4808e..bc84106ac057d7affb0e4d7c5c6ce22dcc2b7943 100644 (file)
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1398,7 +1398,15 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
            && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
                if (hcd->self.uses_dma) {
                        if (urb->num_sgs) {
-                               int n = dma_map_sg(
+                               int n;
+
+                               /* We don't support sg for isoc transfers ! */
+                               if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
+                                       WARN_ON(1);
+                                       return -EINVAL;
+                               }
+
+                               n = dma_map_sg(
                                                hcd->self.controller,
                                                urb->sg,
                                                urb->num_sgs,