[PATCH v4 3/5] PCI: designware-ep: Make dw_pcie_ep_reset_bar() handle 64-bit BARs properly

[Niklas Cassel <niklas.cassel@axis.com>]

Since a 64-bit BAR consists of a BAR pair, we need to write to both
BARs in the BAR pair to clear the BAR properly.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
 drivers/pci/dwc/pcie-designware-ep.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index 946bbdf53c4d..b20b2651caf9 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -22,11 +22,18 @@ void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
 void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
 {
 	u32 reg;
+	u32 val;
 
 	reg = PCI_BASE_ADDRESS_0 + (4 * bar);
+	val = dw_pcie_readl_dbi(pci, reg);
 	dw_pcie_dbi_ro_wr_en(pci);
 	dw_pcie_writel_dbi2(pci, reg, 0x0);
 	dw_pcie_writel_dbi(pci, reg, 0x0);
+	if (!(val & PCI_BASE_ADDRESS_SPACE_IO) &&
+	    (val & PCI_BASE_ADDRESS_MEM_TYPE_64)) {
+		dw_pcie_writel_dbi2(pci, reg + 4, 0x0);
+		dw_pcie_writel_dbi(pci, reg + 4, 0x0);
+	}
 	dw_pcie_dbi_ro_wr_dis(pci);
 }
 
-- 
2.14.2