usb: cdns3: Fix on-chip memory overflow issue

Patch fixes issue caused setting On-chip memory overflow bit in usb_sts
register. The issue occurred because EP_CFG register was set twice
before USB_STS.CFGSTS was set. Every write operation on EP_CFG.BUFFERING
causes that controller increases internal counter holding the number
of reserved on-chip buffers. First time this register was updated in
function cdns3_ep_config before delegating SET_CONFIGURATION request
to class driver and again it was updated when class wanted to enable
endpoint.  This patch fixes this issue by configuring endpoints
enabled by class driver in cdns3_gadget_ep_enable and others just
before status stage.

Cc: stable@vger.kernel.org#v5.8+
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Reported-and-tested-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

1 files changed, 35 insertions, 30 deletions

diff --git a/drivers/usb/cdns3/ep0.c b/drivers/usb/cdns3/ep0.c
index 4761c852d9c4..d3121a32cc68 100644
--- a/drivers/usb/cdns3/ep0.c
+++ b/drivers/usb/cdns3/ep0.c
@@ -137,48 +137,36 @@ static int cdns3_req_ep0_set_configuration(struct cdns3_device *priv_dev,
 					   struct usb_ctrlrequest *ctrl_req)
 {
 	enum usb_device_state device_state = priv_dev->gadget.state;
-	struct cdns3_endpoint *priv_ep;
 	u32 config = le16_to_cpu(ctrl_req->wValue);
 	int result = 0;
-	int i;
 
 	switch (device_state) {
 	case USB_STATE_ADDRESS:
-		/* Configure non-control EPs */
-		for (i = 0; i < CDNS3_ENDPOINTS_MAX_COUNT; i++) {
-			priv_ep = priv_dev->eps[i];
-			if (!priv_ep)
-				continue;
-
-			if (priv_ep->flags & EP_CLAIMED)
-				cdns3_ep_config(priv_ep);
-		}
-
 		result = cdns3_ep0_delegate_req(priv_dev, ctrl_req);
 
-		if (result)
-			return result;
-
-		if (!config) {
-			cdns3_hw_reset_eps_config(priv_dev);
-			usb_gadget_set_state(&priv_dev->gadget,
-					     USB_STATE_ADDRESS);
-		}
+		if (result || !config)
+			goto reset_config;
 
 		break;
 	case USB_STATE_CONFIGURED:
 		result = cdns3_ep0_delegate_req(priv_dev, ctrl_req);
+		if (!config && !result)
+			goto reset_config;
 
-		if (!config && !result) {
-			cdns3_hw_reset_eps_config(priv_dev);
-			usb_gadget_set_state(&priv_dev->gadget,
-					     USB_STATE_ADDRESS);
-		}
 		break;
 	default:
-		result = -EINVAL;
+		return -EINVAL;
 	}
 
+	return 0;
+
+reset_config:
+	if (result != USB_GADGET_DELAYED_STATUS)
+		cdns3_hw_reset_eps_config(priv_dev);
+
+	usb_gadget_set_state(&priv_dev->gadget,
+			     USB_STATE_ADDRESS);
+
 	return result;
 }
 
@@ -705,6 +693,7 @@ static int cdns3_gadget_ep0_queue(struct usb_ep *ep,
 	unsigned long flags;
 	int ret = 0;
 	u8 zlp = 0;
+	int i;
 
 	spin_lock_irqsave(&priv_dev->lock, flags);
 	trace_cdns3_ep0_queue(priv_dev, request);
@@ -720,6 +709,17 @@ static int cdns3_gadget_ep0_queue(struct usb_ep *ep,
 		u32 val;
 
 		cdns3_select_ep(priv_dev, 0x00);
+
+		/*
+		 * Configure all non-control EPs which are not enabled by class driver
+		 */
+		for (i = 0; i < CDNS3_ENDPOINTS_MAX_COUNT; i++) {
+			priv_ep = priv_dev->eps[i];
+			if (priv_ep && priv_ep->flags & EP_CLAIMED &&
+			    !(priv_ep->flags & EP_ENABLED))
+				cdns3_ep_config(priv_ep, 0);
+		}
+
 		cdns3_set_hw_configuration(priv_dev);
 		cdns3_ep0_complete_setup(priv_dev, 0, 1);
 		/* wait until configuration set */
@@ -811,6 +811,7 @@ void cdns3_ep0_config(struct cdns3_device *priv_dev)
 	struct cdns3_usb_regs __iomem *regs;
 	struct cdns3_endpoint *priv_ep;
 	u32 max_packet_size = 64;
+	u32 ep_cfg;
 
 	regs = priv_dev->regs;
 
@@ -842,8 +843,10 @@ void cdns3_ep0_config(struct cdns3_device *priv_dev)
 				       BIT(0) | BIT(16));
 	}
 
-	writel(EP_CFG_ENABLE | EP_CFG_MAXPKTSIZE(max_packet_size),
-	       &regs->ep_cfg);
+	ep_cfg = EP_CFG_ENABLE | EP_CFG_MAXPKTSIZE(max_packet_size);
+
+	if (!(priv_ep->flags & EP_CONFIGURED))
+		writel(ep_cfg, &regs->ep_cfg);
 
 	writel(EP_STS_EN_SETUPEN | EP_STS_EN_DESCMISEN | EP_STS_EN_TRBERREN,
 	       &regs->ep_sts_en);
@@ -851,8 +854,10 @@ void cdns3_ep0_config(struct cdns3_device *priv_dev)
 	/* init ep in */
 	cdns3_select_ep(priv_dev, USB_DIR_IN);
 
-	writel(EP_CFG_ENABLE | EP_CFG_MAXPKTSIZE(max_packet_size),
-	       &regs->ep_cfg);
+	if (!(priv_ep->flags & EP_CONFIGURED))
+		writel(ep_cfg, &regs->ep_cfg);
+
+	priv_ep->flags |= EP_CONFIGURED;
 
 	writel(EP_STS_EN_SETUPEN | EP_STS_EN_TRBERREN, &regs->ep_sts_en);