Hi Ulf, > From: Ulf Hansson <ulf.hans...@linaro.org> > Sent: Wednesday, March 17, 2021 5:31 PM > > Since the introduction of the PM domain support for the scu-pd, the genpd > framework has been continuously improved. More preciously, using a single > global power domain can quite easily be deployed for imx platforms. > > To avoid confusions, let's therefore make an update to the comments about > the missing pieces. > > Signed-off-by: Ulf Hansson <ulf.hans...@linaro.org>
Thanks for the update. Reviewed-by: Dong Aisheng <aisheng.d...@nxp.com> BTW, I'm still uncertain if the new approach can finally work well for i.MX as SCU PD also supports multiple low power state. I could investigate it more when I adding multi low power states support. Regards Aisheng > --- > drivers/firmware/imx/scu-pd.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/firmware/imx/scu-pd.c b/drivers/firmware/imx/scu-pd.c > index 08533ee67626..6e178a63442d 100644 > --- a/drivers/firmware/imx/scu-pd.c > +++ b/drivers/firmware/imx/scu-pd.c > @@ -29,6 +29,10 @@ > * The framework needs some proper extension to support multi power > * domain cases. > * > + * Update: Genpd assigns the ->of_node for the virtual device before it > + * invokes ->attach_dev() callback, hence parsing for device resources via > + * DT should work fine. > + * > * 2. It also breaks most of current drivers as the driver probe sequence > * behavior changed if removing ->power_on|off() callback and use > * ->start() and ->stop() instead. genpd_dev_pm_attach will only power > @@ -39,8 +43,11 @@ > * domain enabled will trigger a HW access error. That means we need fix > * most drivers probe sequence with proper runtime pm. > * > - * In summary, we need fix above two issue before being able to switch to > - * the "single global power domain" way. > + * Update: Runtime PM support isn't necessary. Instead, this can easily be > + * fixed in drivers by adding a call to dev_pm_domain_start() during > probe. > + * > + * In summary, the second part needs to be addressed via minor updates > + to the > + * relevant drivers, before the "single global power domain" model can be > used. > * > */ > > -- > 2.25.1
