According to the section 3.5.7.2 "RC Mode" in DWC PCIe Dual Mode Rev.5.20a, we should disable two BARs to avoid unnecessary memory assignment during device enumeration. Otherwise, Renesas R-Car Gen4 PCIe controllers cannot work correctly in host mode. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> --- drivers/pci/controller/dwc/pcie-designware-host.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index a7170fd0e847..56cc7ff6d508 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -737,6 +737,14 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp) u32 val, ctrl, num_ctrls; int ret; + /* + * According to the section 3.5.7.2 "RC Mode" in DWC PCIe Dual Mode + * Rev.5.20a, we should disable two BARs to avoid unnecessary memory + * assignment during device enumeration. + */ + dw_pcie_writel_dbi2(pci, PCI_BASE_ADDRESS_0, 0x0); + dw_pcie_writel_dbi2(pci, PCI_BASE_ADDRESS_1, 0x0); + /* * Enable DBI read-only registers for writing/updating configuration. * Write permission gets disabled towards the end of this function. -- 2.25.1
