Re: [PATCH v6 08/10] PCI: dw-rockchip: Set broken L1SS resume flag

[Shawn Lin <shawn.lin@rock-chips.com>]

在 2026/09/08 星期二 22:51, Sebastian Reichel 写道:
> Setup the broken_l1ss_resume flag, so that pci_suspend_retains_context()
> returns false on the Rockchip platform allowing PCIe peripheral device
> drivers to act upon.
> 
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> ---
>   drivers/pci/controller/dwc/pcie-dw-rockchip.c | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> index 17530507e41b..47d9cab909bc 100644
> --- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> @@ -458,6 +458,21 @@ static int rockchip_pcie_host_init(struct dw_pcie_rp *pp)
>   	return 0;
>   }
>   
> +static void rockchip_pcie_host_post_init(struct dw_pcie_rp *pp)
> +{
> +	/*
> +	 * During system suspend, the Rockchip RC driver effectively powers off
> +	 * the controller. If the link is in L1SS and the endpoint asserts
> +	 * CLKREQ# to exit L1SS, the time required to wake the system and
> +	 * restore the PHY/REFCLK may exceed the L1SS exit timing
> +	 * (L10_REFCLK_ON + T_COMMONMODE), resulting in Link Down (LDn) and a
> +	 * reset of the endpoint. Set this flag to indicate this limitation to
> +	 * client drivers so that they can avoid relying on device state being
> +	 * preserved during system suspend.
> +	 */

Yes, this is ture for Rockchip platforms that powering off the
controller as well as PHY is a default action during system suspend.

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

> +	pp->bridge->broken_l1ss_resume = true;
> +}
> +
>   static void rockchip_pcie_pme_turn_off(struct dw_pcie_rp *pp)
>   {
>   	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> @@ -497,6 +512,7 @@ static void rockchip_pcie_pme_turn_off(struct dw_pcie_rp *pp)
>   
>   static const struct dw_pcie_host_ops rockchip_pcie_host_ops = {
>   	.init = rockchip_pcie_host_init,
> +	.post_init = rockchip_pcie_host_post_init,
>   	.pme_turn_off = rockchip_pcie_pme_turn_off,
>   };
>   
>