Re: [PATCH] soc: qcom: update config dependencies for QCOM_RPMPD

From: Bjorn Andersson
Date: Wed Jan 30 2019 - 20:33:15 EST


On Fri 18 Jan 09:39 PST 2019, Stephen Boyd wrote:

> Quoting Rajendra Nayak (2019-01-17 20:48:01)
> > drivers/soc/qcom/Kconfig | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> > index a5d5167c3f16..1ee298f6bf17 100644
> > --- a/drivers/soc/qcom/Kconfig
> > +++ b/drivers/soc/qcom/Kconfig
> > @@ -109,7 +109,7 @@ config QCOM_RPMHPD
> >
> > config QCOM_RPMPD
> > bool "Qualcomm RPM Power domain driver"
>
> Just curious, does it need to be bool for some reason?
>

It's unfortunately not possible to have any genpd, iommu or pinctrl
drivers compiled as modules, because once you pass lateinit probe
deferral is purposefully broken. See
driver_deferred_probe_check_state().

This also means that if you're unlucky and your kernel reached lateinit
before the SMD communication with RPM is established and has brought up
the rpmpd, you are left with a completely broken system. Unfortunately
this isn't that hard to reproduce with a minimal defconfig.

Regards,
Bjorn