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usb: dwc3: gadget: issue Update Transfer command after queuing isoc request

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Issue an Update Transfer command after queuing a request to an isoc
EP with an active transfer. This is required according to the dwc3
databook. Pratyush Anand reports that this fixes a problem he was
having with Isoc IN transfers.

Tested-by: Pratyush Anand<pratyush.anand@st.com>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Paul Zimmerman 2012-03-29 18:16:54 +00:00 committed by Felipe Balbi
parent c12a0d862a
commit f898ae09a0
1 changed files with 28 additions and 17 deletions
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45
drivers/usb/dwc3/gadget.c
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@ -957,10 +957,12 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep, u16 cmd_param,
}
dep->flags |= DWC3_EP_BUSY;
dep->res_trans_idx = dwc3_gadget_ep_get_transfer_index(dwc,
dep->number);
WARN_ON_ONCE(!dep->res_trans_idx);
if (start_new) {
dep->res_trans_idx = dwc3_gadget_ep_get_transfer_index(dwc,
dep->number);
WARN_ON_ONCE(!dep->res_trans_idx);
}
return 0;
}
@ -994,28 +996,37 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
list_add_tail(&req->list, &dep->request_list);
if (usb_endpoint_xfer_isoc(dep->desc) && (dep->flags & DWC3_EP_BUSY))
dep->flags |= DWC3_EP_PENDING_REQUEST;
/*
* There is one special case: XferNotReady with
* empty list of requests. We need to kick the
* transfer here in that situation, otherwise
* we will be NAKing forever.
* There are two special cases:
*
* If we get XferNotReady before gadget driver
* has a chance to queue a request, we will ACK
* the IRQ but won't be able to receive the data
* until the next request is queued. The following
* code is handling exactly that.
* 1. XferNotReady with empty list of requests. We need to kick the
* transfer here in that situation, otherwise we will be NAKing
* forever. If we get XferNotReady before gadget driver has a
* chance to queue a request, we will ACK the IRQ but won't be
* able to receive the data until the next request is queued.
* The following code is handling exactly that.
*
* 2. XferInProgress on Isoc EP with an active transfer. We need to
* kick the transfer here after queuing a request, otherwise the
* core may not see the modified TRB(s).
*/
if (dep->flags & DWC3_EP_PENDING_REQUEST) {
int ret;
int start_trans;
int ret;
int start_trans = 1;
u8 trans_idx = dep->res_trans_idx;
start_trans = 1;
if (usb_endpoint_xfer_isoc(dep->desc) &&
(dep->flags & DWC3_EP_BUSY))
(dep->flags & DWC3_EP_BUSY)) {
start_trans = 0;
WARN_ON_ONCE(!trans_idx);
} else {
trans_idx = 0;
}
ret = __dwc3_gadget_kick_transfer(dep, 0, start_trans);
ret = __dwc3_gadget_kick_transfer(dep, trans_idx, start_trans);
if (ret && ret != -EBUSY) {
struct dwc3 *dwc = dep->dwc;