commit cdc5232903cb6e73d5107c9bc2b26bf68db85708
author Felipe Balbi <balbi@ti.com> Wed Sep 24 14:19:52 2014 -0500
committer flintman <flintman@flintmancomputers.com> Mon Apr 27 08:01:52 2015 -0400
tree 4350c5d0bbe52188615c6112bdb75bbd27350df2
parent ef3bba2f7c8615d03259e0852171bf56227fe260

usb: dwc3: gadget: fix set_halt() bug with pending transfers

commit 7a60855972f0d3c014093046cb6f013a1ee5bb19 upstream.

According to our Gadget Framework API documentation,
->set_halt() *must* return -EAGAIN if we have pending
transfers (on either direction) or FIFO isn't empty (on
TX endpoints).

Fix this bug so that the mass storage gadget can be used
without stall=0 parameter.

This patch should be backported to all kernels since v3.2.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <balbi@ti.com>
[lizf: Backported to 3.4:
 - adjust context
 - drop the change to dwc3_gadget_ep_set_wedge()]
Signed-off-by: Zefan Li <lizefan@huawei.com>

drivers/usb/dwc3/gadget.c

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index eefbfda..eba5cd0 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -534,7 +534,7 @@
 
 	/* make sure HW endpoint isn't stalled */
 	if (dep->flags & DWC3_EP_STALL)
-		__dwc3_gadget_ep_set_halt(dep, 0);
+		__dwc3_gadget_ep_set_halt(dep, 0, false);
 
 	reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
 	reg &= ~DWC3_DALEPENA_EP(dep->number);
@@ -1079,7 +1079,7 @@
 	return ret;
 }
 
-int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value)
+int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
 {
 	struct dwc3_gadget_ep_cmd_params	params;
 	struct dwc3				*dwc = dep->dwc;
@@ -1088,6 +1088,14 @@
 	memset(&params, 0x00, sizeof(params));
 
 	if (value) {
+		if (!protocol && ((dep->direction && dep->flags & DWC3_EP_BUSY) ||
+				(!list_empty(&dep->req_queued) ||
+				 !list_empty(&dep->request_list)))) {
+			dev_dbg(dwc->dev, "%s: pending request, cannot halt\n",
+					dep->name);
+			return -EAGAIN;
+		}
+
 		if (dep->number == 0 || dep->number == 1) {
 			/*
 			 * Whenever EP0 is stalled, we will restart
@@ -1136,7 +1144,7 @@
 		goto out;
 	}
 
-	ret = __dwc3_gadget_ep_set_halt(dep, value);
+	ret = __dwc3_gadget_ep_set_halt(dep, value, false);
 out:
 	spin_unlock_irqrestore(&dwc->lock, flags);