PCI: dwc: Suspend/resume rework

[PATCH 1/2] PCI: dwc: Skip PME_Turn_Off broadcast and L2/L3 transition during suspend if link is not up

Posted by Manivannan Sadhasivam 1 week, 5 days ago

During system suspend, if the PCIe link is not up, then there is no need
to broadcast PME_Turn_Off message and wait for L2/L3 transition. So skip
them.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 drivers/pci/controller/dwc/pcie-designware-host.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 20c9333bcb1c..8fe3454f3b13 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -1129,6 +1129,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
 	u32 val;
 	int ret;
 
+	if (!dw_pcie_link_up(pci))
+		goto stop_link;
+
 	/*
 	 * If L1SS is supported, then do not put the link into L2 as some
 	 * devices such as NVMe expect low resume latency.
@@ -1162,6 +1165,7 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
 	 */
 	udelay(1);
 
+stop_link:
 	dw_pcie_stop_link(pci);
 	if (pci->pp.ops->deinit)
 		pci->pp.ops->deinit(&pci->pp);

-- 
2.48.1

Re: [PATCH 1/2] PCI: dwc: Skip PME_Turn_Off broadcast and L2/L3 transition during suspend if link is not up

Posted by Vincent Guittot 1 week, 4 days ago

On Wed, 19 Nov 2025 at 19:10, Manivannan Sadhasivam
<manivannan.sadhasivam@oss.qualcomm.com> wrote:
>
> During system suspend, if the PCIe link is not up, then there is no need
> to broadcast PME_Turn_Off message and wait for L2/L3 transition. So skip
> them.
>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>

> ---
>  drivers/pci/controller/dwc/pcie-designware-host.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 20c9333bcb1c..8fe3454f3b13 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -1129,6 +1129,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>         u32 val;
>         int ret;
>
> +       if (!dw_pcie_link_up(pci))
> +               goto stop_link;
> +
>         /*
>          * If L1SS is supported, then do not put the link into L2 as some
>          * devices such as NVMe expect low resume latency.
> @@ -1162,6 +1165,7 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>          */
>         udelay(1);
>
> +stop_link:
>         dw_pcie_stop_link(pci);
>         if (pci->pp.ops->deinit)
>                 pci->pp.ops->deinit(&pci->pp);
>
> --
> 2.48.1
>

Re: [PATCH 1/2] PCI: dwc: Skip PME_Turn_Off broadcast and L2/L3 transition during suspend if link is not up

Posted by Shawn Lin 1 week, 5 days ago

在 2025/11/20 星期四 2:10, Manivannan Sadhasivam 写道:
> During system suspend, if the PCIe link is not up, then there is no need
> to broadcast PME_Turn_Off message and wait for L2/L3 transition. So skip
> them.
> 

Review-by: Shawn Lin <shawn.lin@rock-chips.com>

> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
> ---
>   drivers/pci/controller/dwc/pcie-designware-host.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 20c9333bcb1c..8fe3454f3b13 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -1129,6 +1129,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>   	u32 val;
>   	int ret;
>   
> +	if (!dw_pcie_link_up(pci))
> +		goto stop_link;
> +
>   	/*
>   	 * If L1SS is supported, then do not put the link into L2 as some
>   	 * devices such as NVMe expect low resume latency.
> @@ -1162,6 +1165,7 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>   	 */
>   	udelay(1);
>   
> +stop_link:
>   	dw_pcie_stop_link(pci);
>   	if (pci->pp.ops->deinit)
>   		pci->pp.ops->deinit(&pci->pp);
>

Re: [PATCH 1/2] PCI: dwc: Skip PME_Turn_Off broadcast and L2/L3 transition during suspend if link is not up

Posted by Frank Li 1 week, 5 days ago

On Wed, Nov 19, 2025 at 11:40:07PM +0530, Manivannan Sadhasivam wrote:
> During system suspend, if the PCIe link is not up, then there is no need
> to broadcast PME_Turn_Off message and wait for L2/L3 transition. So skip
> them.
>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/pci/controller/dwc/pcie-designware-host.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 20c9333bcb1c..8fe3454f3b13 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -1129,6 +1129,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>  	u32 val;
>  	int ret;
>
> +	if (!dw_pcie_link_up(pci))
> +		goto stop_link;
> +
>  	/*
>  	 * If L1SS is supported, then do not put the link into L2 as some
>  	 * devices such as NVMe expect low resume latency.
> @@ -1162,6 +1165,7 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>  	 */
>  	udelay(1);
>
> +stop_link:
>  	dw_pcie_stop_link(pci);
>  	if (pci->pp.ops->deinit)
>  		pci->pp.ops->deinit(&pci->pp);
>
> --
> 2.48.1
>