Re: [PATCH v4 3/9] PCI: epf-mhi: Add support for handling D-state notify from EPC

[Krishna Chaitanya Chundru]

On 7/31/2023 11:05 AM, Krishna Chaitanya Chundru wrote:
> On 7/28/2023 9:39 AM, Manivannan Sadhasivam wrote:
> > On Thu, Jul 13, 2023 at 12:40:12PM +0530, Krishna chaitanya chundru 
> > wrote:
> > > Add support for handling D-state notify for MHI EPF.
> > >
> > > Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> > > ---
> > >   drivers/pci/endpoint/functions/pci-epf-mhi.c | 11 +++++++++++
> > >   include/linux/mhi_ep.h                       |  3 +++
> > >   2 files changed, 14 insertions(+)
> > >
> > > diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c 
> > > b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> > > index 9c1f5a1..ee91bfc 100644
> > > --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
> > > +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> > > @@ -339,6 +339,16 @@ static int pci_epf_mhi_bme(struct pci_epf *epf)
> > >       return 0;
> > >   }
> > >   +static int pci_epf_mhi_dstate_notify(struct pci_epf *epf, 
> > > pci_power_t state)
> > > +{
> > > +    struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
> > > +    struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
> > > +
> > > +    mhi_cntrl->dstate = state;
> > Where is this variable being used? Also, don't we need any locking?
> >
> > - Mani
>
> we are using this variable in wakeup host op which is introduced on 
> patch [PATCH v4 8/9] PCI: epf-mhi: Add wakeup host op
>
> I will add lock in my next series.
>
> - KC

Mani, as this is being called from IRQ context do we need to add any 
lock here.

- KC

> > > +
> > > +    return 0;
> > > +}
> > > +
> > >   static int pci_epf_mhi_bind(struct pci_epf *epf)
> > >   {
> > >       struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
> > > @@ -394,6 +404,7 @@ static struct pci_epc_event_ops 
> > > pci_epf_mhi_event_ops = {
> > >       .link_up = pci_epf_mhi_link_up,
> > >       .link_down = pci_epf_mhi_link_down,
> > >       .bme = pci_epf_mhi_bme,
> > > +    .dstate_notify = pci_epf_mhi_dstate_notify,
> > >   };
> > >     static int pci_epf_mhi_probe(struct pci_epf *epf,
> > > diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
> > > index f198a8a..c3a0685 100644
> > > --- a/include/linux/mhi_ep.h
> > > +++ b/include/linux/mhi_ep.h
> > > @@ -8,6 +8,7 @@
> > >     #include <linux/dma-direction.h>
> > >   #include <linux/mhi.h>
> > > +#include <linux/pci.h>
> > >     #define MHI_EP_DEFAULT_MTU 0x8000
> > >   @@ -139,6 +140,8 @@ struct mhi_ep_cntrl {
> > >         enum mhi_state mhi_state;
> > >   +    pci_power_t dstate;
> > > +
> > >       u32 max_chan;
> > >       u32 mru;
> > >       u32 event_rings;
> > > --
> > > 2.7.4