@@ -731,6 +731,21 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen)
dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, cap | link_speed);
}
+void dw_pcie_link_set_max_cap_width(struct dw_pcie *pci, int num_lanes)
+{
+ u32 val;
+ u8 cap;
+
+ if (!num_lanes)
+ return;
+
+ cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+ val = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP);
+ val &= ~PCI_EXP_LNKCAP_MLW;
+ val |= num_lanes << PCI_EXP_LNKSTA_NLW_SHIFT;
+ dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, val);
+}
+
static void dw_pcie_link_set_max_width(struct dw_pcie *pci, u32 num_lanes)
{
u32 val;
@@ -1067,6 +1082,7 @@ void dw_pcie_setup(struct dw_pcie *pci)
dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, val);
}
+ dw_pcie_link_set_max_cap_width(pci, pci->num_lanes);
dw_pcie_link_set_max_width(pci, pci->num_lanes);
dw_pcie_link_set_max_link_width(pci, pci->num_lanes);
}
Add dw_pcie_link_set_max_cap_width() to set PCI_EXP_LNKCAP_MLW. In accordance with the DW PCIe RC/EP HW manuals [1,2,3,...] aside with the PORT_LINK_CTRL_OFF.LINK_CAPABLE and GEN2_CTRL_OFF.NUM_OF_LANES[8:0] field there is another one which needs to be update. It's LINK_CAPABILITIES_REG.PCIE_CAP_MAX_LINK_WIDTH. If it isn't done at the very least the maximum link-width capability CSR won't expose the actual maximum capability. [1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.60a, March 2015, p.1032 [2] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.70a, March 2016, p.1065 [3] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.90a, March 2016, p.1057 ... [X] DesignWare Cores PCI Express Controller Databook - DWC PCIe Endpoint, Version 5.40a, March 2019, p.1396 [X+1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 5.40a, March 2019, p.1266 The commit description is suggested by Serge Semin. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> --- drivers/pci/controller/dwc/pcie-designware.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)