On 21-03-09 06:19:40, 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 kmalloc and dma_map API to > allocate aligned request buffer of dynamic length. > > Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
The comment with the 1st patch, it is not a bug-fix. > Reported-by: Aswath Govindraju <a-govindr...@ti.com> > Signed-off-by: Sanket Parmar <spar...@cadence.com> > --- > drivers/usb/cdns3/cdns3-gadget.c | 73 +++++++++++++++++++++++++------------ > drivers/usb/cdns3/cdns3-gadget.h | 2 + > 2 files changed, 51 insertions(+), 24 deletions(-) > > diff --git a/drivers/usb/cdns3/cdns3-gadget.c > b/drivers/usb/cdns3/cdns3-gadget.c > index 5f51215..b4955ce 100644 > --- a/drivers/usb/cdns3/cdns3-gadget.c > +++ b/drivers/usb/cdns3/cdns3-gadget.c > @@ -818,10 +818,26 @@ void cdns3_gadget_giveback(struct cdns3_endpoint > *priv_ep, > usb_gadget_unmap_request_by_dev(priv_dev->sysdev, request, > priv_ep->dir); > > - if ((priv_req->flags & REQUEST_UNALIGNED) && > - priv_ep->dir == USB_DIR_OUT && !request->status) > - memcpy(request->buf, priv_req->aligned_buf->buf, > - request->length); > + if ((priv_req->flags & REQUEST_UNALIGNED) && priv_req->aligned_buf) { > + struct cdns3_aligned_buf *buf; > + > + buf = priv_req->aligned_buf; > + dma_unmap_single(priv_dev->sysdev, buf->dma, buf->size, > + buf->dir); > + priv_req->flags &= ~REQUEST_UNALIGNED; > + > + if (priv_ep->dir == USB_DIR_OUT && !request->status) { > + memcpy(request->buf, priv_req->aligned_buf->buf, > + request->length); > + } > + > + trace_cdns3_free_aligned_request(priv_req); > + priv_req->aligned_buf->in_use = 0; > + queue_work(system_freezable_wq, > + &priv_dev->aligned_buf_wq); > + priv_req->aligned_buf = NULL; > + > + } > > priv_req->flags &= ~(REQUEST_PENDING | REQUEST_UNALIGNED); > /* All TRBs have finished, clear the counter */ > @@ -883,8 +899,7 @@ 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); > + kfree(buf->buf); > kfree(buf); > spin_lock_irqsave(&priv_dev->lock, flags); > } > @@ -910,27 +925,16 @@ static int cdns3_prepare_aligned_request_buf(struct > cdns3_request *priv_req) > if (!buf) > return -ENOMEM; > > - buf->size = priv_req->request.length; > + buf->size = usb_endpoint_dir_out(priv_ep->endpoint.desc) ? > + usb_ep_align(&(priv_ep->endpoint), > priv_req->request.length) > + : priv_req->request.length; > > - buf->buf = dma_alloc_coherent(priv_dev->sysdev, > - buf->size, > - &buf->dma, > - GFP_ATOMIC); > + buf->buf = kmalloc(buf->size, GFP_ATOMIC); > if (!buf->buf) { > kfree(buf); > return -ENOMEM; > } > > - if (priv_req->aligned_buf) { > - trace_cdns3_free_aligned_request(priv_req); > - priv_req->aligned_buf->in_use = 0; > - queue_work(system_freezable_wq, > - &priv_dev->aligned_buf_wq); > - } > - > - buf->in_use = 1; > - priv_req->aligned_buf = buf; > - > list_add_tail(&buf->list, > &priv_dev->aligned_buf_list); > } > @@ -940,6 +944,27 @@ static int cdns3_prepare_aligned_request_buf(struct > cdns3_request *priv_req) > priv_req->request.length); > } > > + if (priv_req->aligned_buf) { > + trace_cdns3_free_aligned_request(priv_req); > + priv_req->aligned_buf->in_use = 0; > + queue_work(system_freezable_wq, > + &priv_dev->aligned_buf_wq); @Pawel, do you remember when this condition is met? > + } > + > + buf->dir = priv_ep->dir ? DMA_TO_DEVICE : DMA_FROM_DEVICE; > + buf->in_use = 1; > + priv_req->aligned_buf = buf; > + > + buf->dma = dma_map_single(priv_dev->sysdev, buf->buf, buf->size, > + buf->dir); > + > + if (dma_mapping_error(priv_dev->sysdev, buf->dma)) { > + dev_err(priv_dev->dev, "Failed to map buffer\n"); > + kfree(buf->buf); > + kfree(buf); > + return -EFAULT; > + } > + > priv_req->flags |= REQUEST_UNALIGNED; > trace_cdns3_prepare_aligned_request(priv_req); > > @@ -3088,11 +3113,11 @@ 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, > - buf->buf, > - buf->dma); > + dma_unmap_single(priv_dev->sysdev, buf->dma, buf->size, > + buf->dir); It only needs to DMA unmap after DMA has completed, this buf will not be used, otherwise, the kfree below will cause issue. > > list_del(&buf->list); > + kfree(buf->buf); > 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; > }; > -- > 1.7.1 > -- Thanks, Peter Chen