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usb: dwc3: simplify ZLP handling

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It's much simpler to just add one extra TRB chained to previous TRB to
handle ZLP. This helps us reduce pointless allocations and simplifies
the code a little bit.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Felipe Balbi
2017-04-07 16:34:38 +03:00
parent 4199c5f8bc
commit d6e5a549cc
3 changed files with 59 additions and 83 deletions
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89
drivers/usb/dwc3/gadget.c
View File

@@ -1044,6 +1044,22 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
false, 0, req->request.stream_id,
req->request.short_not_ok,
req->request.no_interrupt);
} else if (req->request.zero && req->request.length &&
(IS_ALIGNED(req->request.length,dep->endpoint.maxpacket))) {
struct dwc3 *dwc = dep->dwc;
struct dwc3_trb *trb;
req->zero = true;
/* prepare normal TRB */
dwc3_prepare_one_trb(dep, req, true, 0);
/* Now prepare one extra TRB to handle ZLP */
trb = &dep->trb_pool[dep->trb_enqueue];
__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
false, 0, req->request.stream_id,
req->request.short_not_ok,
req->request.no_interrupt);
} else {
dwc3_prepare_one_trb(dep, req, false, 0);
}
@@ -1259,31 +1275,6 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
return ret;
}
static void __dwc3_gadget_ep_zlp_complete(struct usb_ep *ep,
struct usb_request *request)
{
dwc3_gadget_ep_free_request(ep, request);
}
static int __dwc3_gadget_ep_queue_zlp(struct dwc3 *dwc, struct dwc3_ep *dep)
{
struct dwc3_request *req;
struct usb_request *request;
struct usb_ep *ep = &dep->endpoint;
request = dwc3_gadget_ep_alloc_request(ep, GFP_ATOMIC);
if (!request)
return -ENOMEM;
request->length = 0;
request->buf = dwc->zlp_buf;
request->complete = __dwc3_gadget_ep_zlp_complete;
req = to_dwc3_request(request);
return __dwc3_gadget_ep_queue(dep, req);
}
static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
gfp_t gfp_flags)
{
@@ -1297,17 +1288,6 @@ static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
spin_lock_irqsave(&dwc->lock, flags);
ret = __dwc3_gadget_ep_queue(dep, req);
/*
* Okay, here's the thing, if gadget driver has requested for a ZLP by
* setting request->zero, instead of doing magic, we will just queue an
* extra usb_request ourselves so that it gets handled the same way as
* any other request.
*/
if (ret == 0 && request->zero && request->length &&
(request->length % ep->maxpacket == 0))
ret = __dwc3_gadget_ep_queue_zlp(dwc, dep);
spin_unlock_irqrestore(&dwc->lock, flags);
return ret;
@@ -1387,7 +1367,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
dwc3_ep_inc_deq(dep);
}
if (r->unaligned) {
if (r->unaligned || r->zero) {
trb = r->trb + r->num_pending_sgs + 1;
trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
dwc3_ep_inc_deq(dep);
@@ -1398,7 +1378,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
dwc3_ep_inc_deq(dep);
if (r->unaligned) {
if (r->unaligned || r->zero) {
trb = r->trb + 1;
trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
dwc3_ep_inc_deq(dep);
@@ -2164,7 +2144,7 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
* with one TRB pending in the ring. We need to manually clear HWO bit
* from that TRB.
*/
if (req->unaligned && (trb->ctrl & DWC3_TRB_CTRL_HWO)) {
if ((req->zero || req->unaligned) && (trb->ctrl & DWC3_TRB_CTRL_HWO)) {
trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
return 1;
}
@@ -2258,11 +2238,12 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
event, status, chain);
}
if (req->unaligned) {
if (req->unaligned || req->zero) {
trb = &dep->trb_pool[dep->trb_dequeue];
ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb,
event, status, false);
req->unaligned = false;
req->zero = false;
}
req->request.actual = length - req->remaining;
@@ -3143,17 +3124,11 @@ int dwc3_gadget_init(struct dwc3 *dwc)
goto err1;
}
dwc->zlp_buf = kzalloc(DWC3_ZLP_BUF_SIZE, GFP_KERNEL);
if (!dwc->zlp_buf) {
ret = -ENOMEM;
goto err2;
}
dwc->bounce = dma_alloc_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE,
&dwc->bounce_addr, GFP_KERNEL);
if (!dwc->bounce) {
ret = -ENOMEM;
goto err3;
goto err2;
}
init_completion(&dwc->ep0_in_setup);
@@ -3193,24 +3168,22 @@ int dwc3_gadget_init(struct dwc3 *dwc)
ret = dwc3_gadget_init_endpoints(dwc, dwc->num_eps);
if (ret)
goto err4;
goto err3;
ret = usb_add_gadget_udc(dwc->dev, &dwc->gadget);
if (ret) {
dev_err(dwc->dev, "failed to register udc\n");
goto err5;
goto err4;
}
return 0;
err5:
dwc3_gadget_free_endpoints(dwc);
err4:
dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
dwc->bounce_addr);
dwc3_gadget_free_endpoints(dwc);
err3:
kfree(dwc->zlp_buf);
dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
dwc->bounce_addr);
err2:
kfree(dwc->setup_buf);
@@ -3228,16 +3201,12 @@ err0:
void dwc3_gadget_exit(struct dwc3 *dwc)
{
usb_del_gadget_udc(&dwc->gadget);
dwc3_gadget_free_endpoints(dwc);
dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
dwc->bounce_addr);
dwc->bounce_addr);
kfree(dwc->setup_buf);
kfree(dwc->zlp_buf);
dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
dwc->ep0_trb, dwc->ep0_trb_addr);
dwc->ep0_trb, dwc->ep0_trb_addr);
}
int dwc3_gadget_suspend(struct dwc3 *dwc)