USB: musb: 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.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index c3d5fc9dfb5bd56f5adc0a3cee337ffd1c31541f..e1fb5d885c18ce6a26cf8f3f18050647682e6309 100644 (file)
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -2512,6 +2512,7 @@ static void musb_free_temp_buffer(struct urb *urb)
 {
        enum dma_data_direction dir;
        struct musb_temp_buffer *temp;
+       size_t length;
 
        if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
                return;
@@ -2522,8 +2523,12 @@ static void musb_free_temp_buffer(struct urb *urb)
                            data);
 
        if (dir == DMA_FROM_DEVICE) {
-               memcpy(temp->old_xfer_buffer, temp->data,
-                      urb->transfer_buffer_length);
+               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);