> -----Original Message-----
> From: Hongxing Zhu
> Sent: 2024年11月7日 16:41
> To: Krzysztof Wilczy?ski <kw@xxxxxxxxx>
> Cc: Bjorn Helgaas <helgaas@xxxxxxxxxx>; bhelgaas@xxxxxxxxxx;
> lorenzo.pieralisi@xxxxxxx; Frank Li <frank.li@xxxxxxx>; mani@xxxxxxxxxx;
> linux-pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx
> Subject: RE: [PATCH v2] PCI: dwc: Fix resume failure if no EP is connected at
> some platforms
>
> > -----Original Message-----
> > From: Krzysztof Wilczy?ski <kw@xxxxxxxxx>
> > Sent: 2024年11月7日 15:20
> > To: Hongxing Zhu <hongxing.zhu@xxxxxxx>
> > Cc: Bjorn Helgaas <helgaas@xxxxxxxxxx>; bhelgaas@xxxxxxxxxx;
> > lorenzo.pieralisi@xxxxxxx; Frank Li <frank.li@xxxxxxx>;
> > mani@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx;
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> > linux-kernel@xxxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx;
> > imx@xxxxxxxxxxxxxxx
> > Subject: Re: [PATCH v2] PCI: dwc: Fix resume failure if no EP is
> > connected at some platforms
> >
> > Hello,
> >
> > > > But I don't think you responded to the race question. What
> > > > happens
> > here?
> > > >
> > > > if (dw_pcie_get_ltssm(pci) > DW_PCIE_LTSSM_DETECT_ACT) {
> > > > --> link goes down here <--
> > > > pci->pp.ops->pme_turn_off(&pci->pp);
> > > >
> > > > You decide the LTSSM is active and the link is up. Then the link
> > > > goes
> > down.
> > > > Then you send PME_Turn_off. Now what?
> > > >
> > > > If it's safe to try to send PME_Turn_off regardless of whether the
> > > > link is up or down, there would be no need to test the LTSSM state.
> > > I made a local tests on i.MX95/i.MX8QM/i.MX8MP/i.MX8MM/i.MX8MQ,
> > and
> > > confirm that it's safe to send PME_TURN_OFF although the link is down.
> > > You're right. It's no need to test LTSSM state here.
> > > So do the L2 poll listed above after PME_TURN_OFF is sent.
> > >
> > > Since the 6.13 merge window is almost closed.
> > > How about I prepare another Fix patch to do the following items for
> > > incoming 6.14?
> > > - Before sending PME_TURN_OFF, don't test the LTSSM stat.
> > > - Remove the L2 stat poll, after sending PME_TURN_OFF.
> >
> > If the changes aren't too involved, then I would rather fix it or drop
> > the not needed code now, before we sent the Pull Request.
> >
> > So, feel free to sent a small patch against the current branch, or
> > simply let me know how do you wish the current code to be changed, so
> > I can do it against the current branch.
> Thanks for your kindly reminder.
> This clean up small patch is on the way.
Here it is.
https://lkml.org/lkml/2024/11/7/409
Thanks.
Best Regards
Richard Zhu
>
> Best Regards
> Richard Zhu
> >
> > Thank you!
> >
> > Krzysztof
