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-govindr...@ti.com>
Signed-off-by: Sanket Parmar <spar...@cadence.com>
---
Changelog:
v3:
- removed extra blank line
v2:
- used dma_*_noncoherent() APIs
- changed the commit log
drivers/usb/cdns3/cdns3-gadget.c | 29 +++++++++++++++++++++++------
drivers/usb/cdns3/cdns3-gadget.h | 2 ++
2 files changed, 25 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 0b892a2..9b1bd41 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 +945,17 @@ 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);
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
