libdce[Android]: Defer rpmsg_dce device open till buffer lock phase

In the current architecture, rpmsg_dce device is opened
during memplugin_open(), which can be called from any process
context. With Android system configured in SE Linux Enforcement
mode, it is not allowed to open rpmsg_dce in any process other than
mediaserver. Hence the device open logic is deferred till
dce buffer lock API where the actual device ioctls are needed.

Change-Id: Iedacfd3327e0ee975a8a492b057aac576d7f7c10
Signed-off-by: Sunita Nadampalli <sunitan@ti.com>

2 files changed, 18 insertions, 8 deletions

diff --git a/libdce_android.c b/libdce_android.c
index 9480926..de6a5c8 100644
--- a/libdce_android.c
+++ b/libdce_android.c
@@ -44,6 +44,7 @@
 
 extern MmRpc_Handle    MmRpcHandle[];
 extern pthread_mutex_t    ipc_mutex;
+int is_ipc_ready = 0;
 
 int dce_buf_lock(int num, size_t *handle)
 {
@@ -53,6 +54,14 @@ int dce_buf_lock(int num, size_t *handle)
 
     pthread_mutex_lock(&ipc_mutex);
 
+    if (!is_ipc_ready) {
+        if (dce_ipc_init(IPU) != MEM_EOK) {
+            pthread_mutex_unlock(&ipc_mutex);
+            return DCE_EIPC_CALL_FAIL;
+        }
+        is_ipc_ready = 0x1234;
+    }
+
     _ASSERT(num > 0, DCE_EINVALID_INPUT);
 
     desc = malloc(num * sizeof(MmRpc_BufDesc));
diff --git a/memplugin_android.c b/memplugin_android.c
index 7235de2..97ea44a 100644
--- a/memplugin_android.c
+++ b/memplugin_android.c
@@ -51,6 +51,7 @@
 int                    OmapDrm_FD  = INVALID_DRM_FD;
 struct omap_device    *OmapDev     = NULL;
 extern pthread_mutex_t    ipc_mutex;
+extern int is_ipc_ready;
 
 int memplugin_open()
 {
@@ -75,14 +76,6 @@ int memplugin_open()
     pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
     pthread_mutex_init(&ipc_mutex, &attr);
 
-    if (dce_ipc_init(IPU) != MEM_EOK) {
-        omap_device_del(OmapDev);
-        OmapDev = NULL;
-        close(OmapDrm_FD);
-        OmapDrm_FD = INVALID_DRM_FD;
-        return MEM_EOPEN_FAILURE;
-    }
-
     return MEM_EOK;
 }
 
@@ -99,7 +92,15 @@ int memplugin_close()
     * this channel is used only for GEM buffer register/unregister,
     * hence call deinit with -1 for the engine table index
     */
+
+    /*Acquire permission to use IPC*/
+    pthread_mutex_lock(&ipc_mutex);
+
     dce_ipc_deinit(IPU, -1);
+    is_ipc_ready = 0;
+
+    /*Relinquish IPC*/
+    pthread_mutex_unlock(&ipc_mutex);
 
     return MEM_EOK;
 }