Unverified Commit 8430e98f authored by Sanket Parmar's avatar Sanket Parmar Committed by Peter Chen
Browse files

usb: cdns3: Optimize DMA request buffer allocation 



dma_alloc_coherent() might fail on the platform with a small
DMA region.

To avoid such failure in cdns3_prepare_aligned_request_buf(),
dma_alloc_coherent() is replaced with dma_alloc_noncoherent()
to allocate aligned request buffer of dynamic length.

Reported-by: default avatarAswath Govindraju <a-govindraju@ti.com>
Signed-off-by: default avatarSanket Parmar <sparmar@cadence.com>
Signed-off-by: default avatarPeter Chen <peter.chen@kernel.org>
parent b9b1eae7

drivers/usb/cdns3/cdns3-gadget.c

+23 −6
Original line number Diff line number Diff line
@@ -819,9 +819,15 @@ void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep, 
					priv_ep->dir);



	if ((priv_req->flags & REQUEST_UNALIGNED) &&

	    priv_ep->dir == USB_DIR_OUT && !request->status)

	    priv_ep->dir == USB_DIR_OUT && !request->status) {

		/* Make DMA buffer CPU accessible */

		dma_sync_single_for_cpu(priv_dev->sysdev,

			priv_req->aligned_buf->dma,

			priv_req->aligned_buf->size,

			priv_req->aligned_buf->dir);

		memcpy(request->buf, priv_req->aligned_buf->buf,

		       request->length);

	}



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

	/* All TRBs have finished, clear the counter */
@@ -883,8 +889,8 @@ static void cdns3_free_aligned_request_buf(struct work_struct *work) 
			 * interrupts.

			 */

			spin_unlock_irqrestore(&priv_dev->lock, flags);

			dma_free_coherent(priv_dev->sysdev, buf->size,

					  buf->buf, buf->dma);

			dma_free_noncoherent(priv_dev->sysdev, buf->size,

					  buf->buf, buf->dma, buf->dir);

			kfree(buf);

			spin_lock_irqsave(&priv_dev->lock, flags);

		}
@@ -911,10 +917,13 @@ static int cdns3_prepare_aligned_request_buf(struct cdns3_request *priv_req) 
			return -ENOMEM;



		buf->size = priv_req->request.length;

		buf->dir = usb_endpoint_dir_in(priv_ep->endpoint.desc) ?

			DMA_TO_DEVICE : DMA_FROM_DEVICE;



		buf->buf = dma_alloc_coherent(priv_dev->sysdev,

		buf->buf = dma_alloc_noncoherent(priv_dev->sysdev,

					      buf->size,

					      &buf->dma,

					      buf->dir,

					      GFP_ATOMIC);

		if (!buf->buf) {

			kfree(buf);
@@ -936,10 +945,17 @@ static int cdns3_prepare_aligned_request_buf(struct cdns3_request *priv_req) 
	}



	if (priv_ep->dir == USB_DIR_IN) {

		/* Make DMA buffer CPU accessible */

		dma_sync_single_for_cpu(priv_dev->sysdev,

			buf->dma, buf->size, buf->dir);

		memcpy(buf->buf, priv_req->request.buf,

		       priv_req->request.length);

	}



	/* Transfer DMA buffer ownership back to device */

	dma_sync_single_for_device(priv_dev->sysdev,

			buf->dma, buf->size, buf->dir);



	priv_req->flags |= REQUEST_UNALIGNED;

	trace_cdns3_prepare_aligned_request(priv_req);
@@ -3088,9 +3104,10 @@ static void cdns3_gadget_exit(struct cdns *cdns) 
		struct cdns3_aligned_buf *buf;



		buf = cdns3_next_align_buf(&priv_dev->aligned_buf_list);

		dma_free_coherent(priv_dev->sysdev, buf->size,

		dma_free_noncoherent(priv_dev->sysdev, buf->size,

				  buf->buf,

				  buf->dma);

				  buf->dma,

				  buf->dir);



		list_del(&buf->list);

		kfree(buf);

drivers/usb/cdns3/cdns3-gadget.h

+2 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#ifndef __LINUX_CDNS3_GADGET

#define __LINUX_CDNS3_GADGET

#include <linux/usb/gadget.h>

#include <linux/dma-direction.h>



/*

 * USBSS-DEV register interface.
@@ -1205,6 +1206,7 @@ struct cdns3_aligned_buf { 
	void			*buf;

	dma_addr_t		dma;

	u32			size;

	enum dma_data_direction dir;

	unsigned		in_use:1;

	struct list_head	list;

};