openwrt/target/linux/generic/pending-4.14/171-usb-dwc2-Fix-inefficien...

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From 81da1738eee68f1961e03bdeb2d60cf0eb4dd713 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Antti=20Sepp=C3=A4l=C3=A4?= <a.seppala@gmail.com>
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 <a.seppala@gmail.com>
---
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;
@@ -2677,9 +2678,14 @@ static void dwc2_free_dma_aligned_buffer
memcpy(&stored_xfer_buffer, urb->transfer_buffer +
urb->transfer_buffer_length, 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;