[PATCH v5 1/6] PCI: dwc: Remove the L1SS check before putting the link into L2

Manivannan Sadhasivam mani at kernel.org
Fri Sep 19 22:58:20 PDT 2025


On Tue, Sep 02, 2025 at 04:01:46PM +0800, Richard Zhu wrote:
> Since this L1SS check is just an encapsulation problem, and the ASPM
> shouldn't leak out here. Remove the L1SS check during L2 entry.
> 

Sorry, I couldnt' decipher this statement. Could you please elaborate?

- Mani

> Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume functionality")
> Signed-off-by: Richard Zhu <hongxing.zhu at nxp.com>
> ---
>  drivers/pci/controller/dwc/pcie-designware-host.c | 8 --------
>  1 file changed, 8 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 952f8594b501..9d46d1f0334b 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -1005,17 +1005,9 @@ static int dw_pcie_pme_turn_off(struct dw_pcie *pci)
>  
>  int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>  {
> -	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>  	u32 val;
>  	int ret;
>  
> -	/*
> -	 * If L1SS is supported, then do not put the link into L2 as some
> -	 * devices such as NVMe expect low resume latency.
> -	 */
> -	if (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) & PCI_EXP_LNKCTL_ASPM_L1)
> -		return 0;
> -
>  	if (pci->pp.ops->pme_turn_off) {
>  		pci->pp.ops->pme_turn_off(&pci->pp);
>  	} else {
> -- 
> 2.37.1
> 

-- 
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