Re: [PATCH v2] PCI: starfive: Enable PCIe controller's runtime PM before probing host bridge

[Mayank Rana]

On 10/11/2024 8:50 PM, Manivannan Sadhasivam wrote:
> On Fri, Oct 11, 2024 at 04:55:30PM -0700, Mayank Rana wrote:
> > PCIe controller device (i.e. PCIe starfive device) is parent to PCIe host
> > bridge device. To enable runtime PM of PCIe host bridge device (child
> > device), it is must to enable parent device's runtime PM to avoid seeing
> > WARN_ON as "Enabling runtime PM for inactive device with active children".
>
> "to avoid seeing the below warning from PM core:
> pcie-starfive 940000000.pcie: Enabling runtime PM for inactive device
> with active children"
ACK

> > Fix this issue by enabling starfive pcie controller device's runtime PM
> > before calling into pci_host_probe() through plda_pcie_host_init().
>
> "before calling pci_host_probe() in plda_pcie_host_init()"
ACK
> > Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > Signed-off-by: Mayank Rana <quic_mrana@xxxxxxxxxxx>
>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
>
> - Mani
>
> > ---
> > v1->v2: Updated commit description based on Bjorn's feedback
> > Link to v1: https://patchwork.kernel.org/project/linux-pci/patch/20241010202950.3263899-1-quic_mrana@xxxxxxxxxxx/
> >   
> >   drivers/pci/controller/plda/pcie-starfive.c | 10 +++++++---
> >   1 file changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/controller/plda/pcie-starfive.c b/drivers/pci/controller/plda/pcie-starfive.c
> > index 0567ec373a3e..e73c1b7bc8ef 100644
> > --- a/drivers/pci/controller/plda/pcie-starfive.c
> > +++ b/drivers/pci/controller/plda/pcie-starfive.c
> > @@ -404,6 +404,9 @@ static int starfive_pcie_probe(struct platform_device *pdev)
> >   	if (ret)
> >   		return ret;
> >   
> > +	pm_runtime_enable(&pdev->dev);
> > +	pm_runtime_get_sync(&pdev->dev);
> > +
> >   	plda->host_ops = &sf_host_ops;
> >   	plda->num_events = PLDA_MAX_EVENT_NUM;
> >   	/* mask doorbell event */
> > @@ -413,11 +416,12 @@ static int starfive_pcie_probe(struct platform_device *pdev)
> >   	plda->events_bitmap <<= PLDA_NUM_DMA_EVENTS;
> >   	ret = plda_pcie_host_init(&pcie->plda, &starfive_pcie_ops,
> >   				  &stf_pcie_event);
> > -	if (ret)
> > +	if (ret) {
> > +		pm_runtime_put_sync(&pdev->dev);
> > +		pm_runtime_disable(&pdev->dev);
> >   		return ret;
> > +	}
> >   
> > -	pm_runtime_enable(&pdev->dev);
> > -	pm_runtime_get_sync(&pdev->dev);
> >   	platform_set_drvdata(pdev, pcie);
> >   
> >   	return 0;
> > --
> > 2.25.1
Regards,
Mayank