On 28/07/2020 08:37, Alain Volmat wrote:
> In case of an error during the initialization of the sensor,
> the video device is still available since created at the
> probe of the dcmi driver. Moreover the device wouldn't
> be released even when removing the module since the release
> is performed as part of the notifier unbind callback
> (not called if no sensor is properly initialized).
>
> This patch move the video device creation with the v4l2 notifier
> bound handler in order to avoid having a video device created when
> an error happen during the pipe (dcmi - sensor) initialization.
>
> This also makes the video device creation symmetric with the
> release which is already done within the notifier unbind handler.
>
> Fixes: 37404f91ef8b ("[media] stm32-dcmi: STM32 DCMI camera interface driver")
> Signed-off-by: Alain Volmat <alain.volmat@xxxxxx>
> ---
> drivers/media/platform/stm32/stm32-dcmi.c | 23 ++++++++++++-----------
> 1 file changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
> index b8931490b83b..5e60d4c6eeeb 100644
> --- a/drivers/media/platform/stm32/stm32-dcmi.c
> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
> @@ -1747,6 +1747,15 @@ static int dcmi_graph_notify_bound(struct v4l2_async_notifier *notifier,
>
> dev_dbg(dcmi->dev, "Subdev \"%s\" bound\n", subdev->name);
>
> + ret = video_register_device(dcmi->vdev, VFL_TYPE_VIDEO, -1);
> + if (ret) {
> + dev_err(dcmi->dev, "Failed to register video device\n");
> + return ret;
> + }
Why in the bound callback? The video device is typically created in the complete
callback, since that's the point where everything is ready.
You should not create a video device unless it is ready for use, and that's only
valid at the end of the complete callback.
Regards,
Hans
> +
> + dev_dbg(dcmi->dev, "Device registered as %s\n",
> + video_device_node_name(dcmi->vdev));
> +
> /*
> * Link this sub-device to DCMI, it could be
> * a parallel camera sensor or a bridge
> @@ -1759,10 +1768,11 @@ static int dcmi_graph_notify_bound(struct v4l2_async_notifier *notifier,
> &dcmi->vdev->entity, 0,
> MEDIA_LNK_FL_IMMUTABLE |
> MEDIA_LNK_FL_ENABLED);
> - if (ret)
> + if (ret) {
> dev_err(dcmi->dev, "Failed to create media pad link with subdev \"%s\"\n",
> subdev->name);
> - else
> + video_unregister_device(dcmi->vdev);
> + } else
> dev_dbg(dcmi->dev, "DCMI is now linked to \"%s\"\n",
> subdev->name);
>
> @@ -1974,15 +1984,6 @@ static int dcmi_probe(struct platform_device *pdev)
> }
> dcmi->vdev->entity.flags |= MEDIA_ENT_FL_DEFAULT;
>
> - ret = video_register_device(dcmi->vdev, VFL_TYPE_VIDEO, -1);
> - if (ret) {
> - dev_err(dcmi->dev, "Failed to register video device\n");
> - goto err_media_entity_cleanup;
> - }
> -
> - dev_dbg(dcmi->dev, "Device registered as %s\n",
> - video_device_node_name(dcmi->vdev));
> -
> /* Buffer queue */
> q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> q->io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF;
>
