From: Johan Hovold <johan@kernel.org>
Date: Thu, 23 Apr 2015 14:06:51 +0000 (+0200)
Subject: USB: ehci-tegra: fix inefficient copy of unaligned buffers
X-Git-Tag: v4.2-rc1~86^2~62
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0efd937e27d5e169031c2bc45d65fe1b0d289454;p=karo-tx-linux.git

USB: ehci-tegra: fix inefficient copy of unaligned buffers

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>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

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);