Re: [PATCH v3 18/18] PCI: j721e: add suspend and resume support

From: Siddharth Vadapalli
Date: Fri Feb 16 2024 - 06:17:21 EST


On 24/02/16 12:09PM, Théo Lebrun wrote:
> Hello,
>
> On Fri Feb 16, 2024 at 11:48 AM CET, Siddharth Vadapalli wrote:
> > On 24/02/15 04:18PM, Thomas Richard wrote:
> > > From: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
> > >
> > > Add suspend and resume support. Only the rc mode is supported.
> > >
> > > During the suspend stage PERST# is asserted, then deasserted during the
> > > resume stage.
> >
> > Wouldn't this imply that the Endpoint device will be reset and therefore
> > lose context? Or is it expected that the driver corresponding to the
> > Endpoint Function in Linux will restore the state on resume, post reset?
>
> This does imply exactly that. Endpoint driver must be able to restore
> context anyway, as system-wide suspend could mean lost power to PCI RC
> controller (eg suspend-to-RAM) or PCI rails (dependent on hardware).

Thank you for confirming.

Regards,
Siddharth.