Hi Peter,
> On 21-03-17 20:13:59, Sanket Parmar wrote:
> > 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: Aswath Govindraju <a-govindraju@xxxxxx>
> > Signed-off-by: Sanket Parmar <sparmar@xxxxxxxxxxx>
> > ---
> >
> > Changelog:
> > v2:
> > - used dma_*_noncoherent() APIs
> > - changed the commit log
> >
> > drivers/usb/cdns3/cdns3-gadget.c | 30 ++++++++++++++++++++++++-----
> -
> > drivers/usb/cdns3/cdns3-gadget.h | 2 ++
> > 2 files changed, 26 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-
> gadget.c
> > index 0b892a2..126087b 100644
> > --- a/drivers/usb/cdns3/cdns3-gadget.c
> > +++ b/drivers/usb/cdns3/cdns3-gadget.c
> > @@ -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 +945,18 @@ 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);
> > +
> > +
>
> One more blank line.
>
> Otherwise, it seems OK for me.
I have remove this blank line. New patch has been posted already.
>
> > priv_req->flags |= REQUEST_UNALIGNED;
> > trace_cdns3_prepare_aligned_request(priv_req);
> >
> > @@ -3088,9 +3105,10 @@ 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);
> > diff --git a/drivers/usb/cdns3/cdns3-gadget.h b/drivers/usb/cdns3/cdns3-
> gadget.h
> > index ecf9b91..c5660f2 100644
> > --- a/drivers/usb/cdns3/cdns3-gadget.h
> > +++ b/drivers/usb/cdns3/cdns3-gadget.h
> > @@ -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;
> > };
> > --
> > 2.4.5
> >
>
> --
>
> Thanks,
> Peter Chen
Thanks,
Sanket
