Port of a Linux commit 17209dfb35a228e597a387bfc83b68093b247f78
Read back the ATU CR2 register to ensure ATU programming is effective
before any subsequent I/O or config space accesses.
Without this, PCI device enumeration is unreliable.
[bhelgaas: changelog, comment]
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Pratyush Anand <pratyush.anand@xxxxxxxxx>
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
---
drivers/pci/pcie-designware.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/pci/pcie-designware.c b/drivers/pci/pcie-designware.c
index 977548f01..f52b67f4f 100644
--- a/drivers/pci/pcie-designware.c
+++ b/drivers/pci/pcie-designware.c
@@ -161,6 +161,8 @@ static int dw_pcie_wr_own_conf(struct pcie_port *pp, int where, int size,
static void dw_pcie_prog_outbound_atu(struct pcie_port *pp, int index,
int type, u64 cpu_addr, u64 pci_addr, u32 size)
{
+ u32 val;
+
dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND | index,
PCIE_ATU_VIEWPORT);
dw_pcie_writel_rc(pp, lower_32_bits(cpu_addr), PCIE_ATU_LOWER_BASE);
@@ -171,6 +173,12 @@ static void dw_pcie_prog_outbound_atu(struct pcie_port *pp, int index,
dw_pcie_writel_rc(pp, upper_32_bits(pci_addr), PCIE_ATU_UPPER_TARGET);
dw_pcie_writel_rc(pp, type, PCIE_ATU_CR1);
dw_pcie_writel_rc(pp, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
+
+ /*
+ * Make sure ATU enable takes effect before any subsequent config
+ * and I/O accesses.
+ */
+ dw_pcie_readl_rc(pp, PCIE_ATU_CR2, &val);
}
int dw_pcie_link_up(struct pcie_port *pp)
--
2.19.1
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