This is a note to let you know that I've just added the patch titled media: sun8i-a83t-mipi-csi2: Register async subdev with no sensor attached to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: media-sun8i-a83t-mipi-csi2-register-async-subdev-wit.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d782b9c3985719acc887d5639e2889da7bcee7fa Author: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> Date: Fri Sep 9 14:39:54 2022 +0100 media: sun8i-a83t-mipi-csi2: Register async subdev with no sensor attached [ Upstream commit 614f6e35a9e214c80270ab942bf58d85066a3e34 ] This allows the device to probe and register its async subdev without a sensor attached. The rationale is that the parent driver might otherwise wait for the subdev to be registered when it should be available (from the fwnode graph endpoint perspective). This is generally not problematic when the MIPI CSI-2 bridge is the only device attached to the parent, but in the case of a CSI controller that can feed from both MIPI CSI-2 and parallel, it would prevent using the parallel sensor due to the parent waiting for the MIPI CSI-2 subdev to register. Fixes: 576d196c522b ("media: sunxi: Add support for the A83T MIPI CSI-2 controller") Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/sun8i_a83t_mipi_csi2.c b/drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/sun8i_a83t_mipi_csi2.c index 5e1c25db7bc4..d993c09a4820 100644 --- a/drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/sun8i_a83t_mipi_csi2.c +++ b/drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2/sun8i_a83t_mipi_csi2.c @@ -536,6 +536,7 @@ sun8i_a83t_mipi_csi2_bridge_setup(struct sun8i_a83t_mipi_csi2_device *csi2_dev) struct v4l2_async_notifier *notifier = &bridge->notifier; struct media_pad *pads = bridge->pads; struct device *dev = csi2_dev->dev; + bool notifier_registered = false; int ret; mutex_init(&bridge->lock); @@ -573,12 +574,17 @@ sun8i_a83t_mipi_csi2_bridge_setup(struct sun8i_a83t_mipi_csi2_device *csi2_dev) notifier->ops = &sun8i_a83t_mipi_csi2_notifier_ops; ret = sun8i_a83t_mipi_csi2_bridge_source_setup(csi2_dev); - if (ret) + if (ret && ret != -ENODEV) goto error_v4l2_notifier_cleanup; - ret = v4l2_async_subdev_nf_register(subdev, notifier); - if (ret < 0) - goto error_v4l2_notifier_cleanup; + /* Only register the notifier when a sensor is connected. */ + if (ret != -ENODEV) { + ret = v4l2_async_subdev_nf_register(subdev, notifier); + if (ret < 0) + goto error_v4l2_notifier_cleanup; + + notifier_registered = true; + } /* V4L2 Subdev */ @@ -589,7 +595,8 @@ sun8i_a83t_mipi_csi2_bridge_setup(struct sun8i_a83t_mipi_csi2_device *csi2_dev) return 0; error_v4l2_notifier_unregister: - v4l2_async_nf_unregister(notifier); + if (notifier_registered) + v4l2_async_nf_unregister(notifier); error_v4l2_notifier_cleanup: v4l2_async_nf_cleanup(notifier);