linux-kernel - Re: [PATCH v1 1/2] PCI: dw-rockchip: Add remove callback for resource cleanup

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Message-ID: <CANAwSgRXcg4tO00SNu77EKdp6Ay6X7+_f-ZoHxgkv1himxdi0Q@mail.gmail.com>
Date: Tue, 28 Oct 2025 15:04:22 +0530
From: Anand Moon <linux.amoon@...il.com>
To: Shawn Lin <shawn.lin@...k-chips.com>
Cc: Lorenzo Pieralisi <lpieralisi@...nel.org>, Krzysztof Wilczyński <kwilczynski@...nel.org>, 
	Manivannan Sadhasivam <mani@...nel.org>, Rob Herring <robh@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>, 
	Heiko Stuebner <heiko@...ech.de>, Niklas Cassel <cassel@...nel.org>, Hans Zhang <18255117159@....com>, 
	Nicolas Frattaroli <nicolas.frattaroli@...labora.com>, 
	"open list:PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERS" <linux-pci@...r.kernel.org>, 
	"moderated list:ARM/Rockchip SoC support" <linux-arm-kernel@...ts.infradead.org>, 
	"open list:ARM/Rockchip SoC support" <linux-rockchip@...ts.infradead.org>, 
	open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1 1/2] PCI: dw-rockchip: Add remove callback for resource cleanup

Hi Shawn,

Thanks for your review comments.

On Tue, 28 Oct 2025 at 05:56, Shawn Lin <shawn.lin@...k-chips.com> wrote:
>
> 在 2025/10/27 星期一 22:55, Anand Moon 写道:
> > Introduce a .remove() callback to the Rockchip DesignWare PCIe
> > controller driver to ensure proper resource deinitialization during
> > device removal. This includes disabling clocks and deinitializing the
> > PCIe PHY.
> >
> > Signed-off-by: Anand Moon <linux.amoon@...il.com>
> > ---
> >   drivers/pci/controller/dwc/pcie-dw-rockchip.c | 11 +++++++++++
> >   1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> > index 87dd2dd188b4..b878ae8e2b3e 100644
> > --- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> > +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> > @@ -717,6 +717,16 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
> >       return ret;
> >   }
> >
> > +static void rockchip_pcie_remove(struct platform_device *pdev)
> > +{
> > +     struct device *dev = &pdev->dev;
> > +     struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
> > +
> > +     /* Perform other cleanups as necessary */
> > +     clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
> > +     rockchip_pcie_phy_deinit(rockchip);
> > +}
>
> Thanks for the patch.
>
> Dou you need to call dw_pcie_host_deinit()?
I feel the rockchip_pcie_phy_deinit will power off the phy
> And I think you should also try to mask PCIE_CLIENT_INTR_MASK_MISC and
> remove the irq domain as well.
>
> if (rockchip->irq_domain) {
>         int virq, j;
>         for (j = 0; j < PCI_NUM_INTX; j++) {
>                 virq = irq_find_mapping(rockchip->irq_domain, j);
>                 if (virq > 0)
>                         irq_dispose_mapping(virq);
>          }
>         irq_set_chained_handler_and_data(rockchip->irq, NULL, NULL);
>         irq_domain_remove(rockchip->irq_domain);
> }
>
I have implemented resource cleanup in rockchip_pcie_remove,
which is invoked when the system is shutting down.
Your feedback on the updated code is welcome.

static void rockchip_pcie_remove(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
        int irq;

        irq = of_irq_get_byname(dev->of_node, "legacy");
        if (irq < 0)
                return;

        /* Perform other cleanups as necessary */
        /* clear up INTR staatus register */
        rockchip_pcie_writel_apb(rockchip, 0xffffffff,
                                 PCIE_CLIENT_INTR_STATUS_MISC);
        if (rockchip->irq_domain) {
                int virq, j;
                for (j = 0; j < PCI_NUM_INTX; j++) {
                        virq = irq_find_mapping(rockchip->irq_domain, j);
                        if (virq > 0)
                                irq_dispose_mapping(virq);
                }
                irq_set_chained_handler_and_data(irq, NULL, NULL);
                irq_domain_remove(rockchip->irq_domain);
        }

        clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
        /* poweroff the phy */
        rockchip_pcie_phy_deinit(rockchip);
        /* release the reset */
        reset_control_assert(rockchip->rst);
        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);
        pm_runtime_no_callbacks(dev);
}

> Another thin I noticed is should we call pm_runtime_* here for hope that
> genpd could be powered donw once removed?
>
I could not find 'genpd' (power domain) used in the PCIe driver
If we have an example to use genpd I will update this.

I am also looking into adding NOIRQ_SYSTEM_SLEEP_PM_OPS

Thanks
-Anand