[PATCH v4 1/6] PCI: dwc: Remove the L1SS check before putting the link into L2

[Hongxing Zhu]

> -----Original Message-----
> From: Hongxing Zhu <hongxing.zhu at nxp.com>
> Sent: 2025年8月22日 16:44
> To: Frank Li <frank.li at nxp.com>; jingoohan1 at gmail.com;
> l.stach at pengutronix.de; lpieralisi at kernel.org; kwilczynski at kernel.org;
> mani at kernel.org; robh at kernel.org; bhelgaas at google.com;
> shawnguo at kernel.org; s.hauer at pengutronix.de; kernel at pengutronix.de;
> festevam at gmail.com
> Cc: linux-pci at vger.kernel.org; linux-arm-kernel at lists.infradead.org;
> imx at lists.linux.dev; linux-kernel at vger.kernel.org; Hongxing Zhu
> <hongxing.zhu at nxp.com>
> Subject: [PATCH v4 1/6] PCI: dwc: Remove the L1SS check before putting the
> link into L2
> 
> Since this L1SS check is just an encapsulation problem, and the ASPM
> shouldn't leak out here. Remove the L1SS check during L2 entry.
> 
> 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 | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 952f8594b5012..1e130091d62a0 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -1009,13 +1009,6 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>  	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;
> -
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -1005,7 +1005,6 @@ 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);

It's my fault that one line is missing to be deleted. This change would be
 added later with other review comments later.
Best Regards
Richard Zhu
>  	if (pci->pp.ops->pme_turn_off) {
>  		pci->pp.ops->pme_turn_off(&pci->pp);
>  	} else {
> --
> 2.37.1