Re: [PATCH v8 10/10] drivers: qcom: rpmh-rsc: allow active requests from wake TCS

[Raju P L S S S N]

Hi,

On 5/12/2018 1:47 AM, Doug Anderson wrote:
> Hi,
>
> On Wed, May 9, 2018 at 10:01 AM, Lina Iyer <ilina@xxxxxxxxxxxxxx> wrote:
> > Some RSCs may only have sleep and wake TCS, i.e, there is no dedicated
> > TCS for active mode request, but drivers may still want to make active
> > requests from these RSCs. In such cases re-purpose the wake TCS to send
> > active state requests.
> >
> > The requirement for this is that the driver is aware that the wake TCS
> > is being repurposed to send active request, hence the sleep and wake
> > TCSes be invalidated before the active request is sent.
> >
> > Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
> > Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> > ---
> >   drivers/soc/qcom/rpmh-rsc.c | 18 +++++++++++++++++-
> >   1 file changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
> > index 68c25ebbbe09..369b9b3eedc5 100644
> > --- a/drivers/soc/qcom/rpmh-rsc.c
> > +++ b/drivers/soc/qcom/rpmh-rsc.c
> > @@ -153,6 +153,7 @@ static struct tcs_group *get_tcs_for_msg(struct rsc_drv *drv,
> >                                           const struct tcs_request *msg)
> >   {
> >          int type;
> > +       struct tcs_group *tcs;
> >
> >          switch (msg->state) {
> >          case RPMH_ACTIVE_ONLY_STATE:
> > @@ -168,7 +169,22 @@ static struct tcs_group *get_tcs_for_msg(struct rsc_drv *drv,
> >                  return ERR_PTR(-EINVAL);
> >          }
> >
> > -       return get_tcs_of_type(drv, type);
> > +       /*
> > +        * If we are making an active request on a RSC that does not have a
> > +        * dedicated TCS for active state use, then re-purpose a wake TCS to
> > +        * send active votes.
> > +        * NOTE: The driver must be aware that this RSC does not have a
> > +        * dedicated AMC, and therefore would invalidate the sleep and wake
> > +        * TCSes before making an active state request.
> > +        */
> > +       tcs = get_tcs_of_type(drv, type);
> > +       if (msg->state == RPMH_ACTIVE_ONLY_STATE && IS_ERR(tcs)) {
> > +               tcs = get_tcs_of_type(drv, WAKE_TCS);
> > +               if (!IS_ERR(tcs))
> > +                       rpmh_rsc_invalidate(drv);
>
> I noticed that rpmh_rsc_invalidate() can return -EAGAIN.  Do you need
> to deal with that here?

Yes. will add the check here.

Thanks,
Raju.

> -Doug