Re: [PATCH v3] PCI: rcar-gen4: Add missing PM ops

[Koichiro Den]

On Mon, Sep 07, 2026 at 06:35:22PM +0200, Marek Vasut wrote:
> The R-Car Gen4 PCIe controller is part of a power domain. On R-Car S4
> and V4H, this is an always-on power domain which is not shut down in
> suspend. On R-Car V4M, this is a dedicated A2PCIPHY power domain,
> which is shut down during suspend, and the controller loses state,
> which prevents the PCIe from working after resume.
> 
> Fix this by adding generic suspend/resume noirq ops for the controller,
> which tear the link down on suspend, and restart it on resume. Use the
> same PM ops on all of R-Car Gen4 to gracefully suspend and resume the
> PCIe link on V4H and S4 too.
> 
> Test case which demonstrates the problem on R-Car V4M:
> "
> $ hexdump -vC /sys/bus/pci/devices/0000:00:00.0/config > /tmp/pre
> $ echo s2idle > /sys/power/mem_sleep
> $ echo platform > /sys/power/pm_test
> $ echo mem > /sys/power/state
> $ hexdump -vC /sys/bus/pci/devices/0000:00:00.0/config > /tmp/post
> $ diff -Naru /tmp/pre /tmp/post
> ...
> -00000000  12 19 32 00 07 05 10 00  00 00 04 06 00 00 01 00
> +00000000  12 19 32 00 07 05 10 00  00 00 00 ff 00 00 80 00
>                                           ^^^^^
>                                     Class 0604->00ff
> "
> 
> Fixes: 0d0c551011df ("PCI: rcar-gen4: Add R-Car Gen4 PCIe controller support for host mode")
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
> ---

The s2idle test with pm_test=platform now passes in EP mode on S4 Spider even
with CONFIG_PCIE_DW_HOST=y. Thanks! Feel free to use the tag for it if it helps.

Tested-by: Koichiro Den <den@xxxxxxxxxxxxx>

> Cc: "Krzysztof Wilczyński" <kwilczynski@xxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Conor Dooley <conor+dt@xxxxxxxxxx>
> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Cc: Koichiro Den <den@xxxxxxxxxxxxx>
> Cc: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
> Cc: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
> Cc: Magnus Damm <magnus.damm@xxxxxxxxx>
> Cc: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
> ---
> V2: - Add TB from Geert for RC mode
>     - Use pm_sleep_ptr()
>     - Call HOST suspend/resume ops only in case the controller is in RC mode
> V3: - Add RB from Geert
>     - Make rcar_gen4_pcie_pm_ops() static
>     - Pull the mode from driver data
> ---
> NOTE: Depends on series
>       https://lore.kernel.org/linux-pci/20260903205153.283553-1-marek.vasut+renesas@xxxxxxxxxxx/
> ---
>  drivers/pci/controller/dwc/pcie-rcar-gen4.c | 25 +++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> index 5690dc32f47e0..8b6a6cab1b83e 100644
> --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> @@ -909,6 +909,26 @@ static int rcar_gen4_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable
>  	return 0;
>  }
>  
> +static int rcar_gen4_pcie_suspend_noirq(struct device *dev)
> +{
> +	struct rcar_gen4_pcie *rcar = dev_get_drvdata(dev);
> +
> +	if (rcar->drvdata->mode != DW_PCIE_RC_TYPE)
> +		return 0;
> +
> +	return dw_pcie_suspend_noirq(&rcar->dw);
> +}
> +
> +static int rcar_gen4_pcie_resume_noirq(struct device *dev)
> +{
> +	struct rcar_gen4_pcie *rcar = dev_get_drvdata(dev);
> +
> +	if (rcar->drvdata->mode != DW_PCIE_RC_TYPE)
> +		return 0;
> +
> +	return dw_pcie_resume_noirq(&rcar->dw);
> +}
> +
>  static struct rcar_gen4_pcie_drvdata drvdata_r8a779f0_pcie = {
>  	.ltssm_control = r8a779f0_pcie_ltssm_control,
>  	.mode = DW_PCIE_RC_TYPE,
> @@ -952,10 +972,15 @@ static const struct of_device_id rcar_gen4_pcie_of_match[] = {
>  };
>  MODULE_DEVICE_TABLE(of, rcar_gen4_pcie_of_match);
>  
> +static DEFINE_NOIRQ_DEV_PM_OPS(rcar_gen4_pcie_pm_ops,
> +			       rcar_gen4_pcie_suspend_noirq,
> +			       rcar_gen4_pcie_resume_noirq);
> +
>  static struct platform_driver rcar_gen4_pcie_driver = {
>  	.driver = {
>  		.name = "pcie-rcar-gen4",
>  		.of_match_table = rcar_gen4_pcie_of_match,
> +		.pm = pm_sleep_ptr(&rcar_gen4_pcie_pm_ops),
>  		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
>  	},
>  	.probe = rcar_gen4_pcie_probe,
> -- 
> 2.53.0
>