From 7d24c1b5a77c71d885fca047d1f25721f6b366e7 Mon Sep 17 00:00:00 2001 From: Mian Yousaf Kaukab Date: Fri, 30 Jan 2015 09:09:31 +0100 Subject: [PATCH] usb: dwc2: gadget: add unaligned buffers support When using DMA, dwc2 requires buffers to be 4 bytes aligned. Use bounce buffers if they are not. Tested-by: Robert Baldyga Acked-by: John Youn Signed-off-by: Mian Yousaf Kaukab Signed-off-by: Felipe Balbi --- drivers/usb/dwc2/core.h | 2 ++ drivers/usb/dwc2/gadget.c | 62 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 63 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h index c750fd3d88b3..485b195126e7 100644 --- a/drivers/usb/dwc2/core.h +++ b/drivers/usb/dwc2/core.h @@ -158,10 +158,12 @@ struct s3c_hsotg_ep { * struct s3c_hsotg_req - data transfer request * @req: The USB gadget request * @queue: The list of requests for the endpoint this is queued for. + * @saved_req_buf: variable to save req.buf when bounce buffers are used. */ struct s3c_hsotg_req { struct usb_request req; struct list_head queue; + void *saved_req_buf; }; #if IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL) || IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE) diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index fc9462aff67f..5e91cf154bba 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -726,6 +726,59 @@ dma_error: return -EIO; } +static int s3c_hsotg_handle_unaligned_buf_start(struct dwc2_hsotg *hsotg, + struct s3c_hsotg_ep *hs_ep, struct s3c_hsotg_req *hs_req) +{ + void *req_buf = hs_req->req.buf; + + /* If dma is not being used or buffer is aligned */ + if (!using_dma(hsotg) || !((long)req_buf & 3)) + return 0; + + WARN_ON(hs_req->saved_req_buf); + + dev_dbg(hsotg->dev, "%s: %s: buf=%p length=%d\n", __func__, + hs_ep->ep.name, req_buf, hs_req->req.length); + + hs_req->req.buf = kmalloc(hs_req->req.length, GFP_ATOMIC); + if (!hs_req->req.buf) { + hs_req->req.buf = req_buf; + dev_err(hsotg->dev, + "%s: unable to allocate memory for bounce buffer\n", + __func__); + return -ENOMEM; + } + + /* Save actual buffer */ + hs_req->saved_req_buf = req_buf; + + if (hs_ep->dir_in) + memcpy(hs_req->req.buf, req_buf, hs_req->req.length); + return 0; +} + +static void s3c_hsotg_handle_unaligned_buf_complete(struct dwc2_hsotg *hsotg, + struct s3c_hsotg_ep *hs_ep, struct s3c_hsotg_req *hs_req) +{ + /* If dma is not being used or buffer was aligned */ + if (!using_dma(hsotg) || !hs_req->saved_req_buf) + return; + + dev_dbg(hsotg->dev, "%s: %s: status=%d actual-length=%d\n", __func__, + hs_ep->ep.name, hs_req->req.status, hs_req->req.actual); + + /* Copy data from bounce buffer on successful out transfer */ + if (!hs_ep->dir_in && !hs_req->req.status) + memcpy(hs_req->saved_req_buf, hs_req->req.buf, + hs_req->req.actual); + + /* Free bounce buffer */ + kfree(hs_req->req.buf); + + hs_req->req.buf = hs_req->saved_req_buf; + hs_req->saved_req_buf = NULL; +} + static int s3c_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags) { @@ -733,6 +786,7 @@ static int s3c_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req, struct s3c_hsotg_ep *hs_ep = our_ep(ep); struct dwc2_hsotg *hs = hs_ep->parent; bool first; + int ret; dev_dbg(hs->dev, "%s: req %p: %d@%p, noi=%d, zero=%d, snok=%d\n", ep->name, req, req->length, req->buf, req->no_interrupt, @@ -743,9 +797,13 @@ static int s3c_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req, req->actual = 0; req->status = -EINPROGRESS; + ret = s3c_hsotg_handle_unaligned_buf_start(hs, hs_ep, hs_req); + if (ret) + return ret; + /* if we're using DMA, sync the buffers as necessary */ if (using_dma(hs)) { - int ret = s3c_hsotg_map_dma(hs, hs_ep, req); + ret = s3c_hsotg_map_dma(hs, hs_ep, req); if (ret) return ret; } @@ -1326,6 +1384,8 @@ static void s3c_hsotg_complete_request(struct dwc2_hsotg *hsotg, if (hs_req->req.status == -EINPROGRESS) hs_req->req.status = result; + s3c_hsotg_handle_unaligned_buf_complete(hsotg, hs_ep, hs_req); + hs_ep->req = NULL; list_del_init(&hs_req->queue); -- 2.30.2