PCI: designware: Ensure ATU is enabled before IO/conf space accesses

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@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Pratyush Anand <pratyush.anand@gmail.com>
This commit is contained in:
Stanimir Varbanov 2015-12-18 14:38:55 +02:00 committed by Bjorn Helgaas
parent 1ec218373b
commit 17209dfb35
1 changed files with 8 additions and 0 deletions

View File

@ -154,6 +154,8 @@ 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);
@ -164,6 +166,12 @@ 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);
}
static struct irq_chip dw_msi_irq_chip = {