Re: [PATCH 1/2] remoteproc: qcom_q6v5_mss: Populate additional devices from DT

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Mon 29 Nov 07:29 CST 2021, Stephan Gerhold wrote:

> Some devices without own memory resources could be placed anywhere in the
> device tree but they logically belong to the modem remote processor. Make
> it possible to probe them when defined under the mpss device tree node
> by calling of_platform_populate().
> 

This seems reasonable, but other "child devices" of the remoteproc
follows the state of the remoteproc instance. So I'm worried that this
will create an inconsistency in that assumption.

> This can be used for BAM-DMUX for example, which provides the WWAN network
> interfaces on some older Qualcomm SoCs such as MSM8916 or MSM8974.
> 

Is there a technical reason for placing the BAM-DMUX within the modem
remoteproc node? Can we simply move it to / ?

Regards,
Bjorn

> Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
> ---
>  drivers/remoteproc/qcom_q6v5_mss.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
> index 43ea8455546c..69f3d1ebf1f1 100644
> --- a/drivers/remoteproc/qcom_q6v5_mss.c
> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
> @@ -1989,8 +1989,14 @@ static int q6v5_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto remove_sysmon_subdev;
>  
> +	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
> +	if (ret)
> +		goto remove_rproc;
> +
>  	return 0;
>  
> +remove_rproc:
> +	rproc_del(rproc);
>  remove_sysmon_subdev:
>  	qcom_remove_sysmon_subdev(qproc->sysmon);
>  remove_subdevs:
> @@ -2010,6 +2016,7 @@ static int q6v5_remove(struct platform_device *pdev)
>  	struct q6v5 *qproc = platform_get_drvdata(pdev);
>  	struct rproc *rproc = qproc->rproc;
>  
> +	of_platform_depopulate(&pdev->dev);
>  	rproc_del(rproc);
>  
>  	qcom_q6v5_deinit(&qproc->q6v5);
> -- 
> 2.34.1
>