USB: ehci-tegra: fix inefficient copy of unaligned buffers

Make sure only to copy any actual data rather than the whole buffer,
when releasing the temporary buffer used for unaligned non-isochronous
transfers.

Compile-tested only.

Signed-off-by: Johan Hovold <johan@kernel.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c
index ff9af29..4031b37 100644 (file)
--- a/drivers/usb/host/ehci-tegra.c
+++ b/drivers/usb/host/ehci-tegra.c
@@ -304,6 +304,7 @@ struct dma_aligned_buffer {
 static void free_dma_aligned_buffer(struct urb *urb)
 {
        struct dma_aligned_buffer *temp;
+       size_t length;
 
        if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
                return;
@@ -311,9 +312,14 @@ static void free_dma_aligned_buffer(struct urb *urb)
        temp = container_of(urb->transfer_buffer,
                struct dma_aligned_buffer, data);
 
-       if (usb_urb_dir_in(urb))
-               memcpy(temp->old_xfer_buffer, temp->data,
-                      urb->transfer_buffer_length);
+       if (usb_urb_dir_in(urb)) {
+               if (usb_pipeisoc(urb->pipe))
+                       length = urb->transfer_buffer_length;
+               else
+                       length = urb->actual_length;
+
+               memcpy(temp->old_xfer_buffer, temp->data, length);
+       }
        urb->transfer_buffer = temp->old_xfer_buffer;
        kfree(temp->kmalloc_ptr);