> > 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. I will remove this. > > > Reported-by: Aswath Govindraju <a-govindraju@xxxxxx> > > Signed-off-by: Sanket Parmar <sparmar@xxxxxxxxxxx> > > --- > > 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. This part is not clear. Aligned DMA buffer is allocated and mapped in cdns3_prepare_aligned_request_buf() and put into aligned_buf_list. While unloading the gadget, We need to undo the same if aligned_buf_list is not empty. Am I missing something here? Also, I will post v2 of this patch which uses dma_*_noncoherent APIs suggested by Christoph Hellwig. > > > > > 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 Thanks, Sanket