From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johan Hovold Subject: [PATCH v2 1/3] USB: musb: fix inefficient copy of unaligned buffers Date: Thu, 23 Apr 2015 16:06:50 +0200 Message-ID: <1429798012-21916-2-git-send-email-johan@kernel.org> References: <1429798012-21916-1-git-send-email-johan@kernel.org> Return-path: In-Reply-To: <1429798012-21916-1-git-send-email-johan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: linux-tegra@vger.kernel.org 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 --- drivers/usb/musb/musb_host.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index c3d5fc9dfb5b..e1fb5d885c18 100644 --- 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); -- 2.0.5