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); + + 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