usb: dwc3: gadget: wait for End Transfer to complete

Instead of just delaying for 100us, we should
actually wait for End Transfer Command Complete
interrupt before moving on. Note that this should
only be done if we're dealing with one of the core
revisions that actually require the interrupt before
moving on.

[ felipe.balbi@linux.intel.com: minor improvements ]

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 41 insertions, 8 deletions

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 4743e53cc295..64d01ff8c119 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -593,11 +593,14 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep,
 		dep->comp_desc = comp_desc;
 		dep->type = usb_endpoint_type(desc);
 		dep->flags |= DWC3_EP_ENABLED;
+		dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING;
 
 		reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
 		reg |= DWC3_DALEPENA_EP(dep->number);
 		dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
 
+		init_waitqueue_head(&dep->wait_end_transfer);
+
 		if (usb_endpoint_xfer_control(desc))
 			return 0;
 
@@ -699,7 +702,7 @@ static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
 	dep->endpoint.desc = NULL;
 	dep->comp_desc = NULL;
 	dep->type = 0;
-	dep->flags = 0;
+	dep->flags &= DWC3_EP_END_TRANSFER_PENDING;
 
 	return 0;
 }
@@ -1783,9 +1786,6 @@ err0:
 
 static void __dwc3_gadget_stop(struct dwc3 *dwc)
 {
-	if (pm_runtime_suspended(dwc->dev))
-		return;
-
 	dwc3_gadget_disable_irq(dwc);
 	__dwc3_gadget_ep_disable(dwc->eps[0]);
 	__dwc3_gadget_ep_disable(dwc->eps[1]);
@@ -1795,9 +1795,30 @@ static int dwc3_gadget_stop(struct usb_gadget *g)
 {
 	struct dwc3		*dwc = gadget_to_dwc(g);
 	unsigned long		flags;
+	int			epnum;
 
 	spin_lock_irqsave(&dwc->lock, flags);
+
+	if (pm_runtime_suspended(dwc->dev))
+		goto out;
+
 	__dwc3_gadget_stop(dwc);
+
+	for (epnum = 2; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
+		struct dwc3_ep  *dep = dwc->eps[epnum];
+
+		if (!dep)
+			continue;
+
+		if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING))
+			continue;
+
+		wait_event_lock_irq(dep->wait_end_transfer,
+				    !(dep->flags & DWC3_EP_END_TRANSFER_PENDING),
+				    dwc->lock);
+	}
+
+out:
 	dwc->gadget_driver	= NULL;
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
@@ -2171,10 +2192,12 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
 {
 	struct dwc3_ep		*dep;
 	u8			epnum = event->endpoint_number;
+	u8			cmd;
 
 	dep = dwc->eps[epnum];
 
-	if (!(dep->flags & DWC3_EP_ENABLED))
+	if (!(dep->flags & DWC3_EP_ENABLED) &&
+	    !(dep->flags & DWC3_EP_END_TRANSFER_PENDING))
 		return;
 
 	if (epnum == 0 || epnum == 1) {
@@ -2215,8 +2238,15 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
 			return;
 		}
 		break;
-	case DWC3_DEPEVT_RXTXFIFOEVT:
 	case DWC3_DEPEVT_EPCMDCMPLT:
+		cmd = DEPEVT_PARAMETER_CMD(event->parameters);
+
+		if (cmd == DWC3_DEPCMD_ENDTRANSFER) {
+			dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING;
+			wake_up(&dep->wait_end_transfer);
+		}
+		break;
+	case DWC3_DEPEVT_RXTXFIFOEVT:
 		break;
 	}
 }
@@ -2269,7 +2299,8 @@ static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum, bool force)
 
 	dep = dwc->eps[epnum];
 
-	if (!dep->resource_index)
+	if ((dep->flags & DWC3_EP_END_TRANSFER_PENDING) ||
+	    !dep->resource_index)
 		return;
 
 	/*
@@ -2313,8 +2344,10 @@ static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum, bool force)
 	dep->resource_index = 0;
 	dep->flags &= ~DWC3_EP_BUSY;
 
-	if (dwc3_is_usb31(dwc) || dwc->revision < DWC3_REVISION_310A)
+	if (dwc3_is_usb31(dwc) || dwc->revision < DWC3_REVISION_310A) {
+		dep->flags |= DWC3_EP_END_TRANSFER_PENDING;
 		udelay(100);
+	}
 }
 
 static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)