Re: [PATCH v4 3/4] firmware: qcom_scm: Add support for Qualcomm Secure Execution Environment SCM interface

From: Johan Hovold
Date: Wed Jun 28 2023 - 08:51:22 EST


On Wed, Jun 28, 2023 at 02:11:07PM +0200, Johan Hovold wrote:
> On Mon, May 29, 2023 at 01:03:50AM +0200, Maximilian Luz wrote:

> > @@ -1496,6 +1903,12 @@ static int qcom_scm_probe(struct platform_device *pdev)
> >
> > __get_convention();
> >
> > + ret = qcom_scm_qseecom_init();
> > + if (ret < 0) {
> > + __scm = NULL;
>
> So as I mentioned in my reply to 2/4, you can still have clients
> registered here when you clear the __scm pointer which they rely on
> after an error.
>
> Not sure how best to handle this, but perhaps registering a qseecom
> platform device here and have it's driver probe defer until scm is
> available would work?
>
> That way you could also separate out the qseecom implementation in a
> separate file (driver) rather than having the ifdef above.

An alternative may be to just warn and continue if
qcom_scm_qseecom_init() fails. It should never return -EPROBE_DEFER
anyway, right?

Johan