From 81da1738eee68f1961e03bdeb2d60cf0eb4dd713 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Antti=20Sepp=C3=A4l=C3=A4?= Date: Thu, 5 Jul 2018 12:06:18 +0300 Subject: [PATCH 2/2] usb: dwc2: Fix inefficient copy of unaligned buffers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make sure only to copy any actual data rather than the whole buffer, when releasing the temporary buffer used for unaligned non-isochronous transfers. Taken directly from commit 0efd937e27d5e ("USB: ehci-tegra: fix inefficient copy of unaligned buffers") Tested with Lantiq xRX200 (MIPS) and RPi Model B Rev 2 (ARM) Signed-off-by: Antti Seppälä --- drivers/usb/dwc2/hcd.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -2669,6 +2669,7 @@ static int dwc2_alloc_split_dma_aligned_ static void dwc2_free_dma_aligned_buffer(struct urb *urb) { void *stored_xfer_buffer; + size_t length; if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER)) return; @@ -2679,9 +2680,14 @@ static void dwc2_free_dma_aligned_buffer dma_get_cache_alignment()), sizeof(urb->transfer_buffer)); - if (usb_urb_dir_in(urb)) - memcpy(stored_xfer_buffer, urb->transfer_buffer, - 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(stored_xfer_buffer, urb->transfer_buffer, length); + } kfree(urb->transfer_buffer); urb->transfer_buffer = stored_xfer_buffer;