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

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

[Marek Vasut]

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@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Koichiro Den <den@valinux.co.jp>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
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@mailbox.org/
---
 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

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@glider.be>
> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---

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@valinux.co.jp>

> Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Koichiro Den <den@valinux.co.jp>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> Cc: Magnus Damm <magnus.damm@gmail.com>
> Cc: Manivannan Sadhasivam <mani@kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-pci@vger.kernel.org
> Cc: linux-renesas-soc@vger.kernel.org
> ---
> 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@mailbox.org/
> ---
>  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
> 

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

[Marek Vasut]

Hello Den-san,

On 9/8/26 3:05 AM, Koichiro Den wrote:
> 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@glider.be>
>> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
>> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
>> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
>> ---
> 
> 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@valinux.co.jp>
Thank you for your test. I would like to ask -- is the EP side of PCIe 
link behaving correctly during suspend/resume cycle on your S4 setup ? 
Does the EP require any special handling during suspend/resume ?

Thank you for your help !

-- 
Best regards,
Marek Vasut

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

[Koichiro Den]

On Tue, Sep 08, 2026 at 06:29:24PM +0200, Marek Vasut wrote:
> Hello Den-san,
> 
> On 9/8/26 3:05 AM, Koichiro Den wrote:
> > 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@glider.be>
> > > Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > > Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > > Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> > > ---
> > 
> > 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@valinux.co.jp>
> Thank you for your test. I would like to ask -- is the EP side of PCIe link
> behaving correctly during suspend/resume cycle on your S4 setup ? Does the
> EP require any special handling during suspend/resume ?

To be clear, what I confirmed was the following:

- The panic I observed with v1 no longer occurs with this newer revision.
- I could create a vNTB EPF after running the test.
- With vNTB/ntb_netdev already connected before the test. ping resumed normally
  afterwards.

Note: I used the suspend test from the commit message on the EP:
  echo s2idle > /sys/power/mem_sleep && \
  echo platform > /sys/power/pm_test && \
  echo mem > /sys/power/state

Based on these, I believe this patch introduces no regression in EP mode on S4.
Any pre-existing EP suspend/resume issues could be addressed separately.

Best regards,
Koichiro

> 
> Thank you for your help !
> 
> -- 
> Best regards,
> Marek Vasut

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

[Marek Vasut]

On 9/9/26 4:17 AM, Koichiro Den wrote:

Hello Den-san,

>>> 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@valinux.co.jp>
>> Thank you for your test. I would like to ask -- is the EP side of PCIe link
>> behaving correctly during suspend/resume cycle on your S4 setup ? Does the
>> EP require any special handling during suspend/resume ?
> 
> To be clear, what I confirmed was the following:
> 
> - The panic I observed with v1 no longer occurs with this newer revision.
> - I could create a vNTB EPF after running the test.
> - With vNTB/ntb_netdev already connected before the test. ping resumed normally
>    afterwards.
> 
> Note: I used the suspend test from the commit message on the EP:
>    echo s2idle > /sys/power/mem_sleep && \
>    echo platform > /sys/power/pm_test && \
>    echo mem > /sys/power/state
> 
> Based on these, I believe this patch introduces no regression in EP mode on S4.
> Any pre-existing EP suspend/resume issues could be addressed separately.

Understood.

Thank you for your help !

-- 
Best regards,
Marek Vasut

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

[Manivannan Sadhasivam]

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@glider.be>
> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

This patch doesn't apply even after applying [1]. Please rebase on top of
pci/controller/dwc-rcar-gen4 branch and repost.

- Mani

[1] https://lore.kernel.org/linux-pci/20260921202823.72620-1-marek.vasut+renesas@mailbox.org

-- 
மணிவண்ணன் சதாசிவம்

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

[Marek Vasut]

On 9/22/26 4:28 PM, Manivannan Sadhasivam wrote:
> 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@glider.be>
>> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
>> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
>> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> 
> This patch doesn't apply even after applying [1]. Please rebase on top of
> pci/controller/dwc-rcar-gen4 branch and repost.
Rebased, retested and V4 submitted. Thanks !