Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934497AbbDWOJ2 (ORCPT ); Thu, 23 Apr 2015 10:09:28 -0400 Received: from mail-la0-f53.google.com ([209.85.215.53]:33216 "EHLO mail-la0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934067AbbDWOJT (ORCPT ); Thu, 23 Apr 2015 10:09:19 -0400 From: Johan Hovold To: Greg Kroah-Hartman , Felipe Balbi , Alan Stern Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Stephen Warren , Thierry Reding , Alexandre Courbot , linux-tegra@vger.kernel.org, Johan Hovold Subject: [PATCH v2 2/3] USB: ehci-tegra: fix inefficient copy of unaligned buffers Date: Thu, 23 Apr 2015 16:06:51 +0200 Message-Id: <1429798012-21916-3-git-send-email-johan@kernel.org> X-Mailer: git-send-email 2.0.5 In-Reply-To: <1429798012-21916-1-git-send-email-johan@kernel.org> References: <1429798012-21916-1-git-send-email-johan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1544 Lines: 49 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 --- drivers/usb/host/ehci-tegra.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c index ff9af29b4e9f..4031b372008e 100644 --- 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); -- 2.0.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/