Camera: Cleanup to prepare() implementation

- Mutexes _might_ be a good idea
- Don't be surprised by behavior that's expected
- Use the existing logging macros

Bug: 20537148
Change-Id: Ie62985a786d7e6645b4e4fe019dd98b02891a1f7

2 files changed, 6 insertions, 11 deletions

diff --git a/services/camera/libcameraservice/api2/CameraDeviceClient.cpp b/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
index 9c4f9cd..b6f6677 100644
--- a/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
+++ b/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
@@ -691,15 +691,10 @@ status_t CameraDeviceClient::prepare(int streamId) {
         return BAD_VALUE;
     }
 
-    // Also returns BAD_VALUE if stream ID was not valid
+    // Also returns BAD_VALUE if stream ID was not valid, or stream already
+    // has been used
     res = mDevice->prepare(streamId);
 
-    if (res == BAD_VALUE) {
-        ALOGE("%s: Camera %d: Unexpected BAD_VALUE when preparing stream, but we"
-              " already checked and the stream ID (%d) should be valid.",
-              __FUNCTION__, mCameraId, streamId);
-    }
-
     return res;
 }
 
diff --git a/services/camera/libcameraservice/device3/Camera3Device.cpp b/services/camera/libcameraservice/device3/Camera3Device.cpp
index d2c2482..445c9c2 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Device.cpp
@@ -1342,6 +1342,8 @@ status_t Camera3Device::flush(int64_t *frameNumber) {
 status_t Camera3Device::prepare(int streamId) {
     ATRACE_CALL();
     ALOGV("%s: Camera %d: Preparing stream %d", __FUNCTION__, mId, streamId);
+    Mutex::Autolock il(mInterfaceLock);
+    Mutex::Autolock l(mLock);
 
     sp<Camera3StreamInterface> stream;
     ssize_t outputStreamIdx = mOutputStreams.indexOfKey(streamId);
@@ -1353,14 +1355,12 @@ status_t Camera3Device::prepare(int streamId) {
     stream = mOutputStreams.editValueAt(outputStreamIdx);
 
     if (stream->isUnpreparable() || stream->hasOutstandingBuffers() ) {
-        ALOGE("%s: Camera %d: Stream %d has already been a request target",
-                __FUNCTION__, mId, streamId);
+        CLOGE("Stream %d has already been a request target", streamId);
         return BAD_VALUE;
     }
 
     if (mRequestThread->isStreamPending(stream)) {
-        ALOGE("%s: Camera %d: Stream %d is already a target in a pending request",
-                __FUNCTION__, mId, streamId);
+        CLOGE("Stream %d is already a target in a pending request", streamId);
         return BAD_VALUE;
     }