RE: [PATCH] tpm/tpm_crb: enter the low power state upon device suspend
From: Winkler, Tomas
Date: Mon Mar 06 2017 - 13:20:45 EST
>
> On Mon, Mar 06, 2017 at 01:53:35AM +0200, Tomas Winkler wrote:
> > This fix enables a platform to enter the idle state (suspend-to-idle)
> >
> > The driver needs to request explicitly go_idle upon completion from
> > the pm suspend handler.
> > The runtime pm is disabled on suspend during prepare state by calling
> > pm_runtime_get_noresume, hence we cannot relay on runtime pm to leave
> > the device in low power state. Symmetrically cmdReady is called upon
> > resume.
> >
> > Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
>
> LGTM
>
> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
>
> PS. What about Fixes? Does this need it?
No, I don't think this is a regression caused by any patch, rather the pm solution was not complete.
Thanks
Tomas
> /Jarkko
>
> > ---
> > drivers/char/tpm/tpm_crb.c | 25 ++++++++++++++++++++++++-
> > 1 file changed, 24 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> > index 86f355b6df1d..d8dfff0fdfce 100644
> > --- a/drivers/char/tpm/tpm_crb.c
> > +++ b/drivers/char/tpm/tpm_crb.c
> > @@ -479,10 +479,33 @@ static int crb_pm_runtime_resume(struct device
> > *dev)
> >
> > return crb_cmd_ready(dev, priv);
> > }
> > +
> > +static int crb_pm_suspend(struct device *dev) {
> > + int ret;
> > +
> > + ret = tpm_pm_suspend(dev);
> > + if (ret)
> > + return ret;
> > +
> > + return crb_pm_runtime_suspend(dev);
> > +}
> > +
> > +static int crb_pm_resume(struct device *dev) {
> > + int ret;
> > +
> > + ret = crb_pm_runtime_resume(dev);
> > + if (ret)
> > + return ret;
> > +
> > + return tpm_pm_resume(dev);
> > +}
> > +
> > #endif /* CONFIG_PM */
> >
> > static const struct dev_pm_ops crb_pm = {
> > - SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
> > + SET_SYSTEM_SLEEP_PM_OPS(crb_pm_suspend, crb_pm_resume)
> > SET_RUNTIME_PM_OPS(crb_pm_runtime_suspend,
> crb_pm_runtime_resume,
> > NULL) };
> >
> > --
> > 2.7.4
> >