Hi Andrzej,
On 2019-03-29 15:05, Andrzej Pietrasiewicz wrote:
> From: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
>
> NOT FOR MERGING
>
> @Minas: can you please test with this patch instead of the original one?
>
> @Marek: can you please verify if null pointer bug exists in this version?
Yes, I've checked it on my test environment and the NULL ptr issue
observed in v2 is fixed. I think it is a good idea to send incremental
patch to mainline with a 'Fixes:' tag.
> This patch adds support for transferring requests, which are
> non-contiguous in physical memory, i.e. the data buffer is described by
> a scatter-list. This allows transferring large requests without relying
> on error-prone contiguous buffer allocations. This way of allocating
> requests is already implemented in functionfs and TCM USB functions and
> automatically used if UDC driver advertises scatter-gather suppport.
>
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
> [mszyprow: fixed null pointer issue, rewrote commit message]
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> [andrzej.p: improved handling zlps]
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx>
> ---
> drivers/usb/dwc2/gadget.c | 107 +++++++++++++++++++++++++++-----------
> 1 file changed, 76 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index e15d8a462085..e76b2e040b4c 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -768,22 +768,13 @@ static u32 dwc2_gadget_get_desc_params(struct dwc2_hsotg_ep *hs_ep, u32 *mask)
> return desc_size;
> }
>
> -/*
> - * dwc2_gadget_config_nonisoc_xfer_ddma - prepare non ISOC DMA desc chain.
> - * @hs_ep: The endpoint
> - * @dma_buff: DMA address to use
> - * @len: Length of the transfer
> - *
> - * This function will iterate over descriptor chain and fill its entries
> - * with corresponding information based on transfer data.
> - */
> -static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
> +static void dwc2_gadget_fill_nonisoc_xfer_ddma_one(struct dwc2_hsotg_ep *hs_ep,
> + struct dwc2_dma_desc **desc,
> dma_addr_t dma_buff,
> - unsigned int len)
> + unsigned int len,
> + bool true_last)
> {
> - struct dwc2_hsotg *hsotg = hs_ep->parent;
> int dir_in = hs_ep->dir_in;
> - struct dwc2_dma_desc *desc = hs_ep->desc_list;
> u32 mps = hs_ep->ep.maxpacket;
> u32 maxsize = 0;
> u32 offset = 0;
> @@ -798,41 +789,82 @@ static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
> hs_ep->desc_count = 1;
>
> for (i = 0; i < hs_ep->desc_count; ++i) {
> - desc->status = 0;
> - desc->status |= (DEV_DMA_BUFF_STS_HBUSY
> + (*desc)->status = 0;
> + (*desc)->status |= (DEV_DMA_BUFF_STS_HBUSY
> << DEV_DMA_BUFF_STS_SHIFT);
>
> if (len > maxsize) {
> if (!hs_ep->index && !dir_in)
> - desc->status |= (DEV_DMA_L | DEV_DMA_IOC);
> + (*desc)->status |= (DEV_DMA_L | DEV_DMA_IOC);
>
> - desc->status |= (maxsize <<
> - DEV_DMA_NBYTES_SHIFT & mask);
> - desc->buf = dma_buff + offset;
> + (*desc)->status |=
> + maxsize << DEV_DMA_NBYTES_SHIFT & mask;
> + (*desc)->buf = dma_buff + offset;
>
> len -= maxsize;
> offset += maxsize;
> } else {
> - desc->status |= (DEV_DMA_L | DEV_DMA_IOC);
> + if (true_last)
> + (*desc)->status |= (DEV_DMA_L | DEV_DMA_IOC);
>
> if (dir_in)
> - desc->status |= (len % mps) ? DEV_DMA_SHORT :
> - ((hs_ep->send_zlp) ? DEV_DMA_SHORT : 0);
> - if (len > maxsize)
> - dev_err(hsotg->dev, "wrong len %d\n", len);
> + (*desc)->status |= (len % mps) ? DEV_DMA_SHORT :
> + ((hs_ep->send_zlp && true_last) ?
> + DEV_DMA_SHORT : 0);
>
> - desc->status |=
> + (*desc)->status |=
> len << DEV_DMA_NBYTES_SHIFT & mask;
> - desc->buf = dma_buff + offset;
> + (*desc)->buf = dma_buff + offset;
> }
>
> - desc->status &= ~DEV_DMA_BUFF_STS_MASK;
> - desc->status |= (DEV_DMA_BUFF_STS_HREADY
> + (*desc)->status &= ~DEV_DMA_BUFF_STS_MASK;
> + (*desc)->status |= (DEV_DMA_BUFF_STS_HREADY
> << DEV_DMA_BUFF_STS_SHIFT);
> - desc++;
> + (*desc)++;
> }
> }
>
> +/*
> + * dwc2_gadget_config_nonisoc_xfer_ddma - prepare non ISOC DMA desc chain.
> + * @hs_ep: The endpoint
> + * @ureq: Request to transfer
> + * @offset: offset in bytes
> + * @len: Length of the transfer
> + *
> + * This function will iterate over descriptor chain and fill its entries
> + * with corresponding information based on transfer data.
> + */
> +static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
> + dma_addr_t dma_buff,
> + unsigned int len)
> +{
> + struct usb_request *ureq = NULL;
> + struct dwc2_dma_desc *desc = hs_ep->desc_list;
> + struct scatterlist *sg;
> + int i;
> + u8 desc_count = 0;
> +
> + if (hs_ep->req)
> + ureq = &hs_ep->req->req;
> +
> + /* non-DMA sg buffer */
> + if (!ureq || !ureq->num_sgs) {
> + dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &desc,
> + dma_buff, len, true);
> + return;
> + }
> +
> + /* DMA sg buffer */
> + for_each_sg(ureq->sg, sg, ureq->num_sgs, i) {
> + dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &desc,
> + sg_dma_address(sg) + sg->offset, sg_dma_len(sg),
> + sg_is_last(sg));
> + desc_count += hs_ep->desc_count;
> + }
> +
> + hs_ep->desc_count = desc_count;
> +}
> +
> /*
> * dwc2_gadget_fill_isoc_desc - fills next isochronous descriptor in chain.
> * @hs_ep: The isochronous endpoint.
> @@ -944,7 +976,13 @@ static void dwc2_gadget_start_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
>
> hs_ep->next_desc = 0;
> list_for_each_entry_safe(hs_req, treq, &hs_ep->queue, queue) {
> - ret = dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma,
> + dma_addr_t dma_addr = hs_req->req.dma;
> +
> + if (hs_req->req.num_sgs) {
> + WARN_ON(hs_req->req.num_sgs > 1);
> + dma_addr = sg_dma_address(hs_req->req.sg);
> + }
> + ret = dwc2_gadget_fill_isoc_desc(hs_ep, dma_addr,
> hs_req->req.length);
> if (ret)
> break;
> @@ -1399,7 +1437,13 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
> */
> if (using_desc_dma(hs) && hs_ep->isochronous) {
> if (hs_ep->target_frame != TARGET_FRAME_INITIAL) {
> - dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma,
> + dma_addr_t dma_addr = hs_req->req.dma;
> +
> + if (hs_req->req.num_sgs) {
> + WARN_ON(hs_req->req.num_sgs > 1);
> + dma_addr = sg_dma_address(hs_req->req.sg);
> + }
> + dwc2_gadget_fill_isoc_desc(hs_ep, dma_addr,
> hs_req->req.length);
> }
> return 0;
> @@ -4386,6 +4430,7 @@ static int dwc2_hsotg_udc_start(struct usb_gadget *gadget,
> hsotg->enabled = 0;
> spin_unlock_irqrestore(&hsotg->lock, flags);
>
> + gadget->sg_supported = using_desc_dma(hsotg);
> dev_info(hsotg->dev, "bound driver %s\n", driver->driver.name);
>
> return 0;
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
