From 824261d3bc8467f6220061f43d22321f1ce50bc3 Mon Sep 17 00:00:00 2001
From: Grissiom <chaos.proton@gmail.com>
Date: Thu, 22 Aug 2013 15:12:00 +0800
Subject: [PATCH] dev/portal: add checks on oflag

It does not make sense to open portal without a flag. One should open a
portal with RT_DEVICE_OFLAG_RDWR in most cases.
---
 components/drivers/src/portal.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/components/drivers/src/portal.c b/components/drivers/src/portal.c
index 82d9d4e802..26977a8259 100644
--- a/components/drivers/src/portal.c
+++ b/components/drivers/src/portal.c
@@ -53,6 +53,9 @@ static rt_err_t _portal_open(rt_device_t dev, rt_uint16_t oflag)
 
     RT_ASSERT(dev);
 
+    if (!oflag)
+        return -RT_ERROR;
+
     portal = (struct rt_portal_device*)dev;
 
     if (oflag & RT_DEVICE_OFLAG_RDONLY)