From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx> The existing fix doesn't actually work because the Class register and interrupt PIN register are read-only, so it must enable the write permission before writing the correct value to these registers. Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx> Acked-By: Joao Pinto <jpinto@xxxxxxxxxxxx> --- V4: - no change drivers/pci/dwc/pcie-designware-host.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c index 157621175147..582f5cc3cd96 100644 --- a/drivers/pci/dwc/pcie-designware-host.c +++ b/drivers/pci/dwc/pcie-designware-host.c @@ -597,10 +597,12 @@ void dw_pcie_setup_rc(struct pcie_port *pp) dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000); /* setup interrupt pins */ + dw_pcie_dbi_ro_wr_en(pci); val = dw_pcie_readl_dbi(pci, PCI_INTERRUPT_LINE); val &= 0xffff00ff; val |= 0x00000100; dw_pcie_writel_dbi(pci, PCI_INTERRUPT_LINE, val); + dw_pcie_dbi_ro_wr_dis(pci); /* setup bus numbers */ val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS); @@ -637,8 +639,12 @@ void dw_pcie_setup_rc(struct pcie_port *pp) dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0); + /* Enable write permission for the DBI read-only register */ + dw_pcie_dbi_ro_wr_en(pci); /* program correct class for RC */ dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI); + /* Better disable write permission right after the update */ + dw_pcie_dbi_ro_wr_dis(pci); dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val); val |= PORT_LOGIC_SPEED_CHANGE; -- 2.14.1
