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usb: dwc3: ep0: add handling for unaligned OUT transfers

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In case we have transfers which aren't aligned
to wMaxPacketSize, we need to be careful with
how we start the transfer with the HW. OUT
transfers _must_ be aligned with wMaxPacketSize
and in order to guarantee that, we use a bounce
buffer.

Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Felipe Balbi 2011-08-27 22:18:09 +03:00
parent 5812b1c236
commit a6829706ce
1 changed files with 32 additions and 5 deletions
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37
drivers/usb/dwc3/ep0.c
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@ -185,10 +185,29 @@ static int __dwc3_gadget_ep0_queue(struct dwc3_ep *dep,
req->epnum = dep->number;
list_add_tail(&req->list, &dep->request_list);
dwc3_map_buffer_to_dma(req);
if (req->request.length == 0) {
ret = dwc3_ep0_start_trans(dwc, dep->number,
dwc->ctrl_req_addr, 0);
} else if ((req->request.length % dep->endpoint.maxpacket)
&& (dep->number == 0)) {
dwc->ep0_bounced = true;
WARN_ON(req->request.length > dep->endpoint.maxpacket);
/*
* REVISIT in case request length is bigger than EP0
* wMaxPacketSize, we will need two chained TRBs to handle
* the transfer.
*/
ret = dwc3_ep0_start_trans(dwc, dep->number,
dwc->ep0_bounce_addr, dep->endpoint.maxpacket);
} else {
dwc3_map_buffer_to_dma(req);
ret = dwc3_ep0_start_trans(dwc, dep->number,
req->request.dma, req->request.length);
}
ret = dwc3_ep0_start_trans(dwc, dep->number, req->request.dma,
req->request.length);
if (ret < 0) {
list_del(&req->list);
dwc3_unmap_buffer_from_dma(req);
@ -655,8 +674,16 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
dwc3_trb_to_nat(dwc->ep0_trb, &trb);
transferred = ur->length - trb.length;
ur->actual += transferred;
if (dwc->ep0_bounced) {
struct dwc3_ep *ep0 = dwc->eps[0];
transferred = min(ur->length, dep->endpoint.maxpacket - trb.length);
memcpy(ur->buf, dwc->ep0_bounce, transferred);
dwc->ep0_bounced = false;
} else {
transferred = ur->length - trb.length;
ur->actual += transferred;
}
if ((epnum & 1) && ur->actual < ur->length) {
/* for some reason we did not get everything out */