[libcamera-devel] [PATCH v2] libcamera: device_enumerator: ensure deviceNode is not empty

[Benjamin Bara]

From: Benjamin Bara <benjamin.bara at skidata.com>

When activating both ISP nodes on the i.MX8MP, but only connecting one
camera sensor, libcamera aborts because it couldn't find the chosen
entity's device node:

[37:54:40.779902250] [3631] DEBUG DeviceEnumerator device_enumerator.cpp:252 Added device /dev/media1: rkisp1
[37:54:40.780196750] [3631] DEBUG DeviceEnumerator device_enumerator_udev.cpp:322 All dependencies for media device /dev/media0 found
[37:54:40.780237875] [3631] DEBUG DeviceEnumerator device_enumerator.cpp:252 Added device /dev/media0: rkisp1
[37:54:40.780505125] [3631] DEBUG Camera camera_manager.cpp:152 Found registered pipeline handler 'PipelineHandlerRkISP1'
[37:54:40.780599875] [3631] DEBUG DeviceEnumerator device_enumerator.cpp:312 Successful match for media device "rkisp1"
[37:54:40.780731375] [3631] ERROR V4L2 v4l2_device.cpp:93 'rkisp1_isp': Failed to open V4L2 device '': No such file or directory

Fix this by skipping empty device nodes:

[37:49:05.172672000] [3603] DEBUG DeviceEnumerator device_enumerator_udev.cpp:322 All dependencies for media device /dev/media1 found
[37:49:05.172720625] [3603] DEBUG DeviceEnumerator device_enumerator.cpp:256 Added device /dev/media1: rkisp1
[37:49:05.172973875] [3603] DEBUG DeviceEnumerator device_enumerator_udev.cpp:322 All dependencies for media device /dev/media0 found
[37:49:05.173012125] [3603] DEBUG DeviceEnumerator device_enumerator.cpp:256 Added device /dev/media0: rkisp1
[37:49:05.173281625] [3603] DEBUG Camera camera_manager.cpp:152 Found registered pipeline handler 'PipelineHandlerRkISP1'
[37:49:05.173376875] [3603] DEBUG DeviceEnumerator device_enumerator.cpp:107 Skip rkisp1_isp: no device node
[37:49:05.173414375] [3603] DEBUG DeviceEnumerator device_enumerator.cpp:316 Successful match for media device "rkisp1"
[37:49:05.173671250] [3603] DEBUG V4L2 v4l2_videodevice.cpp:632 /dev/video1[15:cap]: Opened device platform:rkisp1: rkisp1: rkisp1_stats
[37:49:05.173775125] [3603] DEBUG V4L2 v4l2_videodevice.cpp:632 /dev/video2[16:out]: Opened device platform:rkisp1: rkisp1: rkisp1_params
[37:49:05.173880500] [3603] DEBUG V4L2 v4l2_videodevice.cpp:632 /dev/video0[18:cap]: Opened device platform:rkisp1: rkisp1: rkisp1

Signed-off-by: Benjamin Bara <benjamin.bara at skidata.com>
---
Hi!

Seems like something went wrong with the format of the log in V1 when
copying it.
---
Changes in v2:
- adapt commit message
- Link to v1: https://lists.libcamera.org/pipermail/libcamera-devel/2023-June/038181.html
---
 src/libcamera/device_enumerator.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp
index f2e055de..f2d943d1 100644
--- a/src/libcamera/device_enumerator.cpp
+++ b/src/libcamera/device_enumerator.cpp
@@ -100,9 +100,13 @@ bool DeviceMatch::match(const MediaDevice *device) const
 		bool found = false;
 
 		for (const MediaEntity *entity : device->entities()) {
-			if (name == entity->name()) {
+			if (name == entity->name() && !entity->deviceNode().empty()) {
 				found = true;
 				break;
+			} else if (name == entity->name()) {
+				LOG(DeviceEnumerator, Debug)
+					<< "Skip " << entity->name()
+					<< ": no device node";
 			}
 		}
 

---
base-commit: 0ee9339331c648232e87d2de2ccd5a92cc61cab2
change-id: 20230609-empty-devnode-36dd2647cde0

Best regards,
-- 
Benjamin Bara <benjamin.bara at skidata.com>