2023-05-18 20:57:07

by Frank Li

Subject: [PATCH 2/2] usb: cdns3: optimize OUT transfer by copying only actual received data

Previously, the entire length of the request, which is equal to or greater
than the actual data, was dma synced and memcpy when using the bounce
buffer. Actually only the actual data indicated by request->actual need be
synced and copied.

Signed-off-by: Frank Li <[email protected]>
---
drivers/usb/cdns3/cdns3-gadget.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 09a0882a4e97..ea19253fd2d0 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -809,10 +809,10 @@ void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep,
/* Make DMA buffer CPU accessible */
dma_sync_single_for_cpu(priv_dev->sysdev,
priv_req->aligned_buf->dma,
- priv_req->aligned_buf->size,
+ request->actual,
priv_req->aligned_buf->dir);
memcpy(request->buf, priv_req->aligned_buf->buf,
- request->length);
+ request->actual);
}

priv_req->flags &= ~(REQUEST_PENDING | REQUEST_UNALIGNED);
--
2.34.1

2023-06-04 23:13:40

by Peter Chen

Subject: Re: [PATCH 2/2] usb: cdns3: optimize OUT transfer by copying only actual received data

On 23-05-18 16:49:46, Frank Li wrote:
> Previously, the entire length of the request, which is equal to or greater
> than the actual data, was dma synced and memcpy when using the bounce
> buffer. Actually only the actual data indicated by request->actual need be
> synced and copied.
>
> Signed-off-by: Frank Li <[email protected]>
> ---
> drivers/usb/cdns3/cdns3-gadget.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> index 09a0882a4e97..ea19253fd2d0 100644
> --- a/drivers/usb/cdns3/cdns3-gadget.c
> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> @@ -809,10 +809,10 @@ void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep,
> /* Make DMA buffer CPU accessible */
> dma_sync_single_for_cpu(priv_dev->sysdev,
> priv_req->aligned_buf->dma,
> - priv_req->aligned_buf->size,
> + request->actual,
> priv_req->aligned_buf->dir);
> memcpy(request->buf, priv_req->aligned_buf->buf,
> - request->length);
> + request->actual);
> }

Acked-by: Peter Chen <[email protected]>

>
> priv_req->flags &= ~(REQUEST_PENDING | REQUEST_UNALIGNED);
> --
> 2.34.1
>

--

Thanks,
Peter Chen