dm: usb: ehci: avoid possible NULL dereference

Currently we check in ehci_shutdown() if ctrl is NULL after
dereferencing it.

Before this we have already dereferenced ctrl, ctrl->hccr,
and ctrl->hcor in ehci_get_portsc_register(), ehci_submit_root(),
and hci_common_init().

A better approach is to already check ctrl, ctrl->hccr, and ctrl->hcor
during the initialization in ehci_register() and usb_lowlevel_init()
and signal an error here via the return code.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

drivers/usb/host/ehci-hcd.c

@@ -210,9 +210,6 @@ static int ehci_shutdown(struct ehci_ctrl *ctrl)
 	uint32_t cmd, reg;
 	int max_ports = HCS_N_PORTS(ehci_readl(&ctrl->hccr->cr_hcsparams));
 
-	if (!ctrl || !ctrl->hcor)
-		return -EINVAL;
-
 	cmd = ehci_readl(&ctrl->hcor->or_usbcmd);
 	/* If not run, directly return */
 	if (!(cmd & CMD_RUN))
@@ -1112,6 +1109,8 @@ int usb_lowlevel_init(int index, enum usb_init_type init, void **controller)
 	rc = ehci_hcd_init(index, init, &ctrl->hccr, &ctrl->hcor);
 	if (rc)
 		return rc;
+	if (!ctrl->hccr || !ctrl->hcor)
+		return -1;
 	if (init == USB_INIT_DEVICE)
 		goto done;
 
@@ -1613,11 +1612,14 @@ int ehci_register(struct udevice *dev, struct ehci_hccr *hccr,
 {
 	struct usb_bus_priv *priv = dev_get_uclass_priv(dev);
 	struct ehci_ctrl *ctrl = dev_get_priv(dev);
-	int ret;
+	int ret = -1;
 
 	debug("%s: dev='%s', ctrl=%p, hccr=%p, hcor=%p, init=%d\n", __func__,
 	      dev->name, ctrl, hccr, hcor, init);
 
+	if (!ctrl || !hccr || !hcor)
+		goto err;
+
 	priv->desc_before_addr = true;
 
 	ehci_setup_ops(ctrl, ops);