commit 44d5f626b449430f97243e2bb8b4ec41dfae6ff7
author Jayant Chowdhary <jchowdhary@google.com> Wed Sep 20 03:11:41 2023 +0000
committer Jayant Chowdhary <jchowdhary@google.com> Thu Sep 21 00:09:46 2023 +0000
tree 57e03a763bc999b081126fabe26b0e72e5d99717
parent 35b1ff9298facd6aaa38af7deb86837585b41901

Fix deadlock when notifyPhysicalCameraDevice is called while waitUntilDrained hasn't completed

The following situation is possible :

thread 1: handling waitUntilIdle from client holds Camera3Device::mInterfaceLock and waits for the
    HAL to drain all results.
    android::Camera3Device::waitUntilStateThenRelock()
    android::Camera3Device::waitUntilDrainedLocked()
    android::Camera3Device::waitUntilDrained()
    android::CameraDeviceClient::waitUntilIdle()

thread 2: handling processCaptureResult callback from the HAL waits on Camera3Device::mInterfaceLock
    NonPI::MutexLockWithTimeout()
    android::Camera3Device::setRotateAndCropAutoBehavior()
    android::Camera2ClientBase<android::CameraDeviceClientBase>::notifyPhysicalCameraChange()
    android::camera3::processCaptureResult()

setRotateAndCropAutoBehaviour() in this case, is an effect of a HAL
callback and shouldn't hold mInterfaceLock. Since mLock already protects
the rotate and crop state we can do without holding mInterfaceLock when
called from processCaptureResult.

Bug: 298705937
Bug: 299348355

Test: GCA (basic validity)
Test: Camera CTS
Test: trigger notifyPhysicalCameraDevice from processCaptureResult while
      Camera3Device::waitUntilDrained() is still executing, no deadlock
      observed.

Change-Id: If6a89ebc7d38510eece00dfbee62af01b5b5b065
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>

services/camera/libcameraservice/api2/CameraDeviceClient.cpp

diff --git a/services/camera/libcameraservice/api2/CameraDeviceClient.cpp b/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
index 1720b55..06f96f3 100644
--- a/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
+++ b/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
@@ -1761,11 +1761,11 @@
     return mDevice->setCameraServiceWatchdog(enabled);
 }
 
-status_t CameraDeviceClient::setRotateAndCropOverride(uint8_t rotateAndCrop) {
+status_t CameraDeviceClient::setRotateAndCropOverride(uint8_t rotateAndCrop, bool fromHal) {
     if (rotateAndCrop > ANDROID_SCALER_ROTATE_AND_CROP_AUTO) return BAD_VALUE;
 
     return mDevice->setRotateAndCropAutoBehavior(
-        static_cast<camera_metadata_enum_android_scaler_rotate_and_crop_t>(rotateAndCrop));
+        static_cast<camera_metadata_enum_android_scaler_rotate_and_crop_t>(rotateAndCrop), fromHal);
 }
 
 status_t CameraDeviceClient::setAutoframingOverride(uint8_t autoframingValue) {