On Thu, Jan 07, 2016 at 02:12:38PM +0800, Jisheng Zhang wrote: > 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 to programming the > translation component then do the required access, so we ignore the ATU > programming for these platforms. Add the comment to explain the reason. > > As Bjorn pointed out, > > "these definitions: > > #define PCIE_ATU_TYPE_MEM > #define PCIE_ATU_TYPE_IO > #define PCIE_ATU_TYPE_CFG0 > #define PCIE_ATU_TYPE_CFG1 > > and these uses: > > - In dw_pcie_host_init(), set PCIE_ATU_TYPE_MEM for unit 1 > (but only if rd_other_conf is not overridden) > > - In dw_pcie_rd_other_conf() and dw_pcie_wr_other_conf(), > set PCIE_ATU_TYPE_CFG0 before config access to own bus; > set PCIE_ATU_TYPE_CFG1 before config access to other bus; > set PCIE_ATU_TYPE_IO after completion > > Why is that initialization related to rd_other_conf? Shouldn't that > be set up always? A comment here would be nice..." > > To be honest, I can't answer this question immediately until I read the > code carefully again. So indeed, the comment is really necessary. > > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx> Applied to pci/host-designware for v4.6, thanks, Jisheng! > --- > drivers/pci/host/pcie-designware.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c > index 02a7452..b795b20 100644 > --- a/drivers/pci/host/pcie-designware.c > +++ b/drivers/pci/host/pcie-designware.c > @@ -517,6 +517,12 @@ 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 > + * doesn't support ATU, it uses its own address translation component > + * rather than ATU, so we should ignore ATU programming for this > + * kind of platform. > + */ > if (!pp->ops->rd_other_conf) > dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1, > PCIE_ATU_TYPE_MEM, pp->mem_base, > -- > 2.7.0.rc3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
