android: Return -EUSERS when failed to open a Camera that's in use

The correct return value for the HAL for hal_dev_open() when trying to
open a camera that's already opened is EUSERS. Make hal_dev_open()
return -EUSERS, and plumb the logic for this through
CameraHalManager::open().

This allows the following CTS tests to pass:
- android.hardware.camera2.cts.CameraManagerTest#testCameraManagerOpenAllCameras
- android.hardware.camera2.cts.MultiViewTest#testDualCameraPreview

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/android/camera3_hal.cpp b/src/android/camera3_hal.cpp
index d6e04af2..08773d33 100644
--- a/src/android/camera3_hal.cpp
+++ b/src/android/camera3_hal.cpp
@@ -77,11 +77,11 @@ static int hal_dev_open(const hw_module_t *module, const char *name,
 	LOG(HAL, Debug) << "Open camera " << name;
 
 	int id = atoi(name);
-	CameraDevice *camera = cameraManager.open(id, module);
+	auto [camera, ret] = cameraManager.open(id, module);
 	if (!camera) {
 		LOG(HAL, Error)
 			<< "Failed to open camera module '" << id << "'";
-		return -ENODEV;
+		return ret == -EBUSY ? -EUSERS : ret;
 	}
 
 	*device = &camera->camera3Device()->common;