On Sat, Oct 3, 2026 at 5:31 AM Dave Klotz <[email protected]> wrote:
>
> The driver decides the link is up when the LTSSM state in the
> DesignWare PORT_DEBUG0 register reads L0. L0 is a physical layer state;
> the data link layer may not be up yet, and config requests sent before
> it is are lost.
>
> Linux's pcie-spacemit-k1 driver reads the link status register in the
> "link" window instead, and needs both SMLH_LINK_UP (physical layer) and
> RDLH_LINK_UP (data link layer); FreeBSD's spacemit_pcie driver does the
> same. The window is already mapped (as phy_ahb) and the bits already
> defined, but nothing read them. Use them, and drop the now unused
> PORT_DEBUG0 definitions.
>
> Signed-off-by: Dave Klotz <[email protected]>
> ---
> drivers/pci/pcie_dw_spacemit.c | 9 ++++++---
> drivers/pci/pcie_dw_spacemit.h | 5 -----
> 2 files changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/pcie_dw_spacemit.c b/drivers/pci/pcie_dw_spacemit.c
> index 5e0871986b..3394ddbd18 100644
> --- a/drivers/pci/pcie_dw_spacemit.c
> +++ b/drivers/pci/pcie_dw_spacemit.c
> @@ -81,10 +81,13 @@ static int is_link_up(struct pcie_dw_spacemit *pci)
> {
> u32 val;
>
> - val = readl(pci->dw.dbi_base + PCIE_PORT_DEBUG0);
> - val &= PORT_LOGIC_LTSSM_STATE_MASK;
> + /*
> + * As in Linux, the link is up once both the physical layer (SMLH)
> + * and the data link layer (RDLH) report it.
> + */
> + val = spacemit_pcie_phy_ahb_readl(pci, K1X_PHY_AHB_LINK_STS);
>
> - return (val == PORT_LOGIC_LTSSM_STATE_L0);
> + return (val & SMLH_LINK_UP) && (val & RDLH_LINK_UP);
> }
>
> static int wait_link_up(struct pcie_dw_spacemit *pci)
> diff --git a/drivers/pci/pcie_dw_spacemit.h b/drivers/pci/pcie_dw_spacemit.h
> index 2c17f113b7..6f198f7d58 100644
> --- a/drivers/pci/pcie_dw_spacemit.h
> +++ b/drivers/pci/pcie_dw_spacemit.h
> @@ -22,11 +22,6 @@
> #define PCIE_MISC_CONTROL_1_OFF 0x8bc
> #define PCIE_DBI_RO_WR_EN BIT(0)
>
> -#define PLR_OFFSET 0x700
> -#define PCIE_PORT_DEBUG0 (PLR_OFFSET + 0x28)
> -#define PORT_LOGIC_LTSSM_STATE_MASK 0x1f
> -#define PORT_LOGIC_LTSSM_STATE_L0 0x11
> -
> #define PCIE_LINK_UP_TIMEOUT_MS 1000
>
> /* Vendor and device IDs */
> --
> 2.55.0
>
>
Reviewed-by: Eric Chung <[email protected]>
