[libcamera-devel] [PATCH RFC] 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 add a new dependency on android's libhardware [1]

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

Fixes: c58662c5770e ("android: Introduce PlatformFrameBufferAllocator")
Signed-off-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
---
RFC as this adds an additional link-time dependency on an AOSP project
(libhardware) and I'm unsure how to handle this.

I thought of using the subprojects structure as done for libyuv but
since libhardware has other AOSP deps (like libvnksupport) I'm not sure
this is appropriate.

Any thoughts on this?
---
 src/android/mm/generic_frame_buffer_allocator.cpp | 5 +++--
 1 file changed, 3 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..58e6c68c4998 100644
--- a/src/android/mm/generic_frame_buffer_allocator.cpp
+++ b/src/android/mm/generic_frame_buffer_allocator.cpp
@@ -72,9 +72,10 @@ 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 +86,7 @@ public:
 
 private:
 	const CameraDevice *const cameraDevice_;
-	struct hw_module_t *const hardwareModule_;
+	const struct hw_module_t *hardwareModule_;
 	struct alloc_device_t *allocDevice_;
 };
 

---
base-commit: 58e0b6e18c425072a47594f42fc0b61801403aca
change-id: 20230227-android-gralloc-04e31d5edc68

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