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

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Message-ID: <CANAwSgQ4HH=16Gn45XP3+jr+V+PrDhh8fC1Ek0jzrbMnhXo9fw@mail.gmail.com>
Date: Wed, 29 Oct 2025 11:54:16 +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,

On Wed, 29 Oct 2025 at 05:58, Shawn Lin <shawn.lin@...k-chips.com> wrote:
>
>
> 在 2025/10/28 星期二 17:34, Anand Moon 写道:
> > 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 */
>
> release? Or "reset the controller"?
>
Ok, I will fix this.
> >          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
>
> That sounds good, you can pick up my patch[1] if you'd like to continue
> addressing the comments that I haven't had time to think more.
>
> [1] https://www.spinics.net/lists/linux-pci/msg171846.html
>
Ok, thanks. I will carefully study and address the comments.

Thanks
-Anand