[libcamera-devel] [PATCH v4] android: mm: generic: use GRALLOC_HARDWARE_MODULE_ID

[Mattijs Korpershoek]

PlatformFrameBufferAllocator is an abstraction over gralloc.
Right now hardwareModule_ points towards a CAMERA_HARDWARE_MODULE_ID.

When gralloc_open() is called we observe:
libcamera: DEBUG HAL camera3_hal.cpp:75 Open camera gpu0
libcamera: ERROR Camera camera.cpp:524 Camera in Configured state trying acquire() requiring state Available
01-23 14:14:04.742   370   416 E libcamera: FATAL HAL generic_frame_buffer_allocator.cpp:105 gralloc_open() failed: -87

Which is wrong, gralloc_open() is attempting to re-open the camera HAL,
instead of the gralloc HAL.

Point to a GRALLOC_HARDWARE_MODULE_ID instead so that we can request
buffers from gralloc in android.

Note: this adds new dependencies on android's libhardware [1] and on libdl.

[1] https://android.googlesource.com/platform/hardware/libhardware

Fixes: c58662c5770e ("android: Introduce PlatformFrameBufferAllocator")
Signed-off-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
---
* Tested on an integration branch in Android 12 (Using android.bp)
* Build tested with meson setup build -Dandroid=enabled -Dandroid_platform=generic

(Laurent, I dropped your reviewed-by since there are additional changes)
---
Changes in v4:
- Add missing meson.build change to link against libdl
- Link to v3: https://lists.libcamera.org/pipermail/libcamera-devel/2023-May/037926.html

Changes in v3:
- Add missing meson.build change to define libhardware dependency
- Link to v2: https://lists.libcamera.org/pipermail/libcamera-devel/2023-February/036884.html

Changes in v2:
- Add dlclose() in PlatformFrameBufferAllocator destructor (Laurent)
- Removed RFC, as linking against an AOSP lib for android is OK.
- Link to v1: https://lists.libcamera.org/pipermail/libcamera-devel/2023-February/036857.html
---
 src/android/mm/generic_frame_buffer_allocator.cpp | 7 +++++--
 src/android/mm/meson.build                        | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/android/mm/generic_frame_buffer_allocator.cpp b/src/android/mm/generic_frame_buffer_allocator.cpp
index 3750e1bf52a9..7ecef2c669df 100644
--- a/src/android/mm/generic_frame_buffer_allocator.cpp
+++ b/src/android/mm/generic_frame_buffer_allocator.cpp
@@ -5,6 +5,7 @@
  * generic_camera_buffer.cpp - Allocate FrameBuffer using gralloc API
  */
 
+#include <dlfcn.h>
 #include <memory>
 #include <vector>
 
@@ -72,9 +73,10 @@ class PlatformFrameBufferAllocator::Private : public Extensible::Private
 public:
 	Private(CameraDevice *const cameraDevice)
 		: cameraDevice_(cameraDevice),
-		  hardwareModule_(cameraDevice->camera3Device()->common.module),
+		  hardwareModule_(nullptr),
 		  allocDevice_(nullptr)
 	{
+		hw_get_module(GRALLOC_HARDWARE_MODULE_ID, &hardwareModule_);
 		ASSERT(hardwareModule_);
 	}
 
@@ -85,7 +87,7 @@ public:
 
 private:
 	const CameraDevice *const cameraDevice_;
-	struct hw_module_t *const hardwareModule_;
+	const struct hw_module_t *hardwareModule_;
 	struct alloc_device_t *allocDevice_;
 };
 
@@ -93,6 +95,7 @@ PlatformFrameBufferAllocator::Private::~Private()
 {
 	if (allocDevice_)
 		gralloc_close(allocDevice_);
+	dlclose(hardwareModule_->dso);
 }
 
 std::unique_ptr<HALFrameBuffer>
diff --git a/src/android/mm/meson.build b/src/android/mm/meson.build
index d40a3b0ba2eb..c92416bd3a6f 100644
--- a/src/android/mm/meson.build
+++ b/src/android/mm/meson.build
@@ -4,6 +4,7 @@ platform = get_option('android_platform')
 if platform == 'generic'
     android_hal_sources += files(['generic_camera_buffer.cpp',
                                   'generic_frame_buffer_allocator.cpp'])
+    android_deps += [libdl, dependency('libhardware')]
 elif platform == 'cros'
     android_hal_sources += files(['cros_camera_buffer.cpp',
                                   'cros_frame_buffer_allocator.cpp'])

---
base-commit: 76e1cb9f7176b4e7a935295d4e633ee24a0fef67
change-id: 20230227-android-gralloc-04e31d5edc68

Best regards,
-- 
Mattijs Korpershoek <mkorpershoek at baylibre.com>