Messages in this thread Patch in this message | | | From | 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 |
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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> --- 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
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