USB: dwc3-msm: Perform DBM config/unconfig under spinlock protection

There is a possibility of dwc3_msm_ep_queue() and msm_ep_unconfig() racing
each other if suspend happens right after configured. This scenario will
result in NOC error if start_xfer command gets queued after
msm_ep_unconfig().  Hence fix the issue by adding spinlock protection for
DBM endpoint configuration and unconfiguration.

Change-Id: I3fd007647370250017c97faebffadb35afb7fc4d
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>

6 files changed, 39 insertions, 19 deletions

diff --git a/drivers/usb/dwc3/dwc3-msm.c b/drivers/usb/dwc3/dwc3-msm.c
index 7447efebed7a..beff34569392 100644
--- a/drivers/usb/dwc3/dwc3-msm.c
+++ b/drivers/usb/dwc3/dwc3-msm.c
@@ -640,6 +640,14 @@ static int dwc3_msm_ep_queue(struct usb_ep *ep,
 		return -EPERM;
 	}
 
+	if (!mdwc->original_ep_ops[dep->number]) {
+		dev_err(mdwc->dev,
+			"ep [%s,%d] was unconfigured as msm endpoint\n",
+			ep->name, dep->number);
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		return -EINVAL;
+	}
+
 	if (!request) {
 		dev_err(mdwc->dev, "%s: request is NULL\n", __func__);
 		spin_unlock_irqrestore(&dwc->lock, flags);
@@ -647,14 +655,11 @@ static int dwc3_msm_ep_queue(struct usb_ep *ep,
 	}
 
 	if (!(request->udc_priv & MSM_SPS_MODE)) {
-		/* Not SPS mode, call original queue */
-		dev_vdbg(mdwc->dev, "%s: not sps mode, use regular queue\n",
+		dev_err(mdwc->dev, "%s: sps mode is not set\n",
 					__func__);
 
 		spin_unlock_irqrestore(&dwc->lock, flags);
-		return (mdwc->original_ep_ops[dep->number])->queue(ep,
-								request,
-								gfp_flags);
+		return -EINVAL;
 	}
 
 	/* HW restriction regarding TRB size (8KB) */
@@ -1331,8 +1336,7 @@ static int dwc3_msm_gsi_ep_op(struct usb_ep *ep,
  *
  * @return int - 0 on success, negetive on error.
  */
-int msm_ep_config(struct usb_ep *ep, struct usb_request *request,
-							gfp_t gfp_flags)
+int msm_ep_config(struct usb_ep *ep, struct usb_request *request)
 {
 	struct dwc3_ep *dep = to_dwc3_ep(ep);
 	struct dwc3 *dwc = dep->dwc;
@@ -1344,23 +1348,27 @@ int msm_ep_config(struct usb_ep *ep, struct usb_request *request,
 	bool disable_wb;
 	bool internal_mem;
 	bool ioc;
+	unsigned long flags;
 
 
+	spin_lock_irqsave(&dwc->lock, flags);
 	/* Save original ep ops for future restore*/
 	if (mdwc->original_ep_ops[dep->number]) {
 		dev_err(mdwc->dev,
 			"ep [%s,%d] already configured as msm endpoint\n",
 			ep->name, dep->number);
+		spin_unlock_irqrestore(&dwc->lock, flags);
 		return -EPERM;
 	}
 	mdwc->original_ep_ops[dep->number] = ep->ops;
 
 	/* Set new usb ops as we like */
-	new_ep_ops = kzalloc(sizeof(struct usb_ep_ops), gfp_flags);
+	new_ep_ops = kzalloc(sizeof(struct usb_ep_ops), GFP_ATOMIC);
 	if (!new_ep_ops) {
 		dev_err(mdwc->dev,
 			"%s: unable to allocate mem for new usb ep ops\n",
 			__func__);
+		spin_unlock_irqrestore(&dwc->lock, flags);
 		return -ENOMEM;
 	}
 	(*new_ep_ops) = (*ep->ops);
@@ -1368,8 +1376,10 @@ int msm_ep_config(struct usb_ep *ep, struct usb_request *request,
 	new_ep_ops->gsi_ep_op = dwc3_msm_gsi_ep_op;
 	ep->ops = new_ep_ops;
 
-	if (!mdwc->dbm || !request || (dep->endpoint.ep_type == EP_TYPE_GSI))
+	if (!mdwc->dbm || !request || (dep->endpoint.ep_type == EP_TYPE_GSI)) {
+		spin_unlock_irqrestore(&dwc->lock, flags);
 		return 0;
+	}
 
 	/*
 	 * Configure the DBM endpoint if required.
@@ -1385,9 +1395,12 @@ int msm_ep_config(struct usb_ep *ep, struct usb_request *request,
 	if (ret < 0) {
 		dev_err(mdwc->dev,
 			"error %d after calling dbm_ep_config\n", ret);
+		spin_unlock_irqrestore(&dwc->lock, flags);
 		return ret;
 	}
 
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
 	return 0;
 }
 EXPORT_SYMBOL(msm_ep_config);
@@ -1407,12 +1420,15 @@ int msm_ep_unconfig(struct usb_ep *ep)
 	struct dwc3 *dwc = dep->dwc;
 	struct dwc3_msm *mdwc = dev_get_drvdata(dwc->dev->parent);
 	struct usb_ep_ops *old_ep_ops;
+	unsigned long flags;
 
+	spin_lock_irqsave(&dwc->lock, flags);
 	/* Restore original ep ops */
 	if (!mdwc->original_ep_ops[dep->number]) {
 		dev_err(mdwc->dev,
 			"ep [%s,%d] was not configured as msm endpoint\n",
 			ep->name, dep->number);
+		spin_unlock_irqrestore(&dwc->lock, flags);
 		return -EINVAL;
 	}
 	old_ep_ops = (struct usb_ep_ops	*)ep->ops;
@@ -1424,8 +1440,10 @@ int msm_ep_unconfig(struct usb_ep *ep)
 	 * Do HERE more usb endpoint un-configurations
 	 * which are specific to MSM.
 	 */
-	if (!mdwc->dbm || (dep->endpoint.ep_type == EP_TYPE_GSI))
+	if (!mdwc->dbm || (dep->endpoint.ep_type == EP_TYPE_GSI)) {
+		spin_unlock_irqrestore(&dwc->lock, flags);
 		return 0;
+	}
 
 	if (dep->busy_slot == dep->free_slot && list_empty(&dep->request_list)
 					 && list_empty(&dep->req_queued)) {
@@ -1446,6 +1464,8 @@ int msm_ep_unconfig(struct usb_ep *ep)
 			dbm_event_buffer_config(mdwc->dbm, 0, 0, 0);
 	}
 
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
 	return 0;
 }
 EXPORT_SYMBOL(msm_ep_unconfig);
diff --git a/drivers/usb/gadget/function/f_gsi.c b/drivers/usb/gadget/function/f_gsi.c
index 84b60ec771a4..d3e01f71fa2f 100644
--- a/drivers/usb/gadget/function/f_gsi.c
+++ b/drivers/usb/gadget/function/f_gsi.c
@@ -2245,7 +2245,7 @@ skip_string_id_alloc:
 		if (!ep)
 			goto fail;
 		gsi->d_port.in_ep = ep;
-		msm_ep_config(gsi->d_port.in_ep, NULL, GFP_KERNEL);
+		msm_ep_config(gsi->d_port.in_ep, NULL);
 		ep->driver_data = cdev;	/* claim */
 	}
 
@@ -2255,7 +2255,7 @@ skip_string_id_alloc:
 		if (!ep)
 			goto fail;
 		gsi->d_port.out_ep = ep;
-		msm_ep_config(gsi->d_port.out_ep, NULL, GFP_KERNEL);
+		msm_ep_config(gsi->d_port.out_ep, NULL);
 		ep->driver_data = cdev;	/* claim */
 	}
 
diff --git a/drivers/usb/gadget/function/u_bam.c b/drivers/usb/gadget/function/u_bam.c
index bc3dd69dcb00..bbb744b33c3a 100644
--- a/drivers/usb/gadget/function/u_bam.c
+++ b/drivers/usb/gadget/function/u_bam.c
@@ -1395,7 +1395,7 @@ static void gbam2bam_connect_work(struct work_struct *w)
 								d->src_pipe_idx;
 		d->rx_req->length = 32*1024;
 		d->rx_req->udc_priv = sps_params;
-		msm_ep_config(port->port_usb->out, d->rx_req, GFP_ATOMIC);
+		msm_ep_config(port->port_usb->out, d->rx_req);
 
 		/* Configure for TX */
 		configure_data_fifo(d->usb_bam_type, d->dst_connection_idx,
@@ -1403,7 +1403,7 @@ static void gbam2bam_connect_work(struct work_struct *w)
 		sps_params = MSM_SPS_MODE | MSM_DISABLE_WB | d->dst_pipe_idx;
 		d->tx_req->length = 32*1024;
 		d->tx_req->udc_priv = sps_params;
-		msm_ep_config(port->port_usb->in, d->tx_req, GFP_ATOMIC);
+		msm_ep_config(port->port_usb->in, d->tx_req);
 
 	} else {
 		/* Configure for RX */
diff --git a/drivers/usb/gadget/function/u_bam_data.c b/drivers/usb/gadget/function/u_bam_data.c
index 226af4bf1595..e479907e93ef 100644
--- a/drivers/usb/gadget/function/u_bam_data.c
+++ b/drivers/usb/gadget/function/u_bam_data.c
@@ -935,7 +935,7 @@ static void bam2bam_data_connect_work(struct work_struct *w)
 			| MSM_PRODUCER | d->src_pipe_idx;
 		d->rx_req->length = 32*1024;
 		d->rx_req->udc_priv = sps_params;
-		msm_ep_config(port->port_usb->out, d->rx_req, GFP_ATOMIC);
+		msm_ep_config(port->port_usb->out, d->rx_req);
 
 		/* Configure TX */
 		configure_usb_data_fifo(d->usb_bam_type,
@@ -945,7 +945,7 @@ static void bam2bam_data_connect_work(struct work_struct *w)
 					| d->dst_pipe_idx;
 		d->tx_req->length = 32*1024;
 		d->tx_req->udc_priv = sps_params;
-		msm_ep_config(port->port_usb->in, d->tx_req, GFP_ATOMIC);
+		msm_ep_config(port->port_usb->in, d->tx_req);
 
 	} else {
 		/* Configure RX */
diff --git a/drivers/usb/gadget/function/u_data_ipa.c b/drivers/usb/gadget/function/u_data_ipa.c
index 1850aa6ea19d..51d95f6c01d4 100644
--- a/drivers/usb/gadget/function/u_data_ipa.c
+++ b/drivers/usb/gadget/function/u_data_ipa.c
@@ -457,7 +457,7 @@ static void ipa_data_connect_work(struct work_struct *w)
 		configure_fifo(port->usb_bam_type,
 				port->src_connection_idx,
 				port->port_usb->out);
-		ret = msm_ep_config(gport->out, port->rx_req, GFP_ATOMIC);
+		ret = msm_ep_config(gport->out, port->rx_req);
 		if (ret) {
 			pr_err("msm_ep_config() failed for OUT EP\n");
 			usb_bam_free_fifos(port->usb_bam_type,
@@ -475,7 +475,7 @@ static void ipa_data_connect_work(struct work_struct *w)
 		port->tx_req->udc_priv = sps_params;
 		configure_fifo(port->usb_bam_type,
 				port->dst_connection_idx, gport->in);
-		ret = msm_ep_config(gport->in, port->tx_req, GFP_ATOMIC);
+		ret = msm_ep_config(gport->in, port->tx_req);
 		if (ret) {
 			pr_err("msm_ep_config() failed for IN EP\n");
 			goto unconfig_msm_ep_out;
diff --git a/drivers/usb/gadget/function/u_qdss.c b/drivers/usb/gadget/function/u_qdss.c
index e26f0977b9b7..42a9cda68659 100644
--- a/drivers/usb/gadget/function/u_qdss.c
+++ b/drivers/usb/gadget/function/u_qdss.c
@@ -99,7 +99,7 @@ static int init_data(struct usb_ep *ep)
 
 	pr_debug("init_data\n");
 
-	res = msm_ep_config(ep, qdss->endless_req, GFP_ATOMIC);
+	res = msm_ep_config(ep, qdss->endless_req);
 	if (res)
 		pr_err("msm_ep_config failed\n");