From dd193929d91e1b44b90f81509feeff10c94ddc4d Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 7 Jan 2016 14:12:38 +0800 Subject: [PATCH] PCI: designware: Explain why we don't program ATU for some platforms Some platforms don't support ATU, e.g., pci-keystone.c. These platforms use their own address translation component rather than ATU, and they provide the rd_other_conf and wr_other_conf methods to program the translation component and perform the access. Add a comment to explain why we don't program the ATU for these platforms. [bhelgaas: changelog] Signed-off-by: Jisheng Zhang Signed-off-by: Bjorn Helgaas --- drivers/pci/host/pcie-designware.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c index 21716827847a..8bcaed18f0dd 100644 --- a/drivers/pci/host/pcie-designware.c +++ b/drivers/pci/host/pcie-designware.c @@ -517,6 +517,11 @@ int dw_pcie_host_init(struct pcie_port *pp) if (pp->ops->host_init) pp->ops->host_init(pp); + /* + * If the platform provides ->rd_other_conf, it means the platform + * uses its own address translation component rather than ATU, so + * we should not program the ATU here. + */ if (!pp->ops->rd_other_conf) dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1, PCIE_ATU_TYPE_MEM, pp->mem_base, -- 2.20.1