On Mon, Sep 19, 2022 at 08:03:40PM +0530, Vidya Sagar wrote:
> Dual mode DesignWare PCIe IP has PTM capability enabled (if supported) even
> in the EP mode. The PCIe compliance for the EP mode expects PTM
> capabilities (ROOT_CAPABLE, RES_CAPABLE, CLK_GRAN) be disabled.
> Hence disable PTM for the EP mode.
"PCIe compliance" - what is this referring to ?
Was this reported to Synopsys ?
Thanks,
Lorenzo
> Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
> ---
> .../pci/controller/dwc/pcie-designware-ep.c | 19 ++++++++++++++++++-
> 1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 7e9529ae3824..dc3057b18f36 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -646,7 +646,7 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
> struct dw_pcie_ep_func *ep_func;
> struct device *dev = pci->dev;
> struct pci_epc *epc = ep->epc;
> - unsigned int offset;
> + unsigned int offset, ptm_cap_base;
> unsigned int nbars;
> u8 hdr_type;
> u8 func_no;
> @@ -698,6 +698,7 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
> }
>
> offset = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_REBAR);
> + ptm_cap_base = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_PTM);
>
> dw_pcie_dbi_ro_wr_en(pci);
>
> @@ -710,6 +711,22 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
> dw_pcie_writel_dbi(pci, offset + PCI_REBAR_CAP, 0x0);
> }
>
> + /*
> + * PTM responder capability can be disabled only after disabling
> + * PTM root capability.
> + */
> + if (ptm_cap_base) {
> + dw_pcie_dbi_ro_wr_en(pci);
> + reg = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
> + reg &= ~PCI_PTM_CAP_ROOT;
> + dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, reg);
> +
> + reg = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
> + reg &= ~(PCI_PTM_CAP_RES | PCI_PTM_GRANULARITY_MASK);
> + dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, reg);
> + dw_pcie_dbi_ro_wr_dis(pci);
> + }
> +
> dw_pcie_setup(pci);
> dw_pcie_dbi_ro_wr_dis(pci);
>
> --
> 2.17.1
>
