| Message ID | 1452147158-2526-1-git-send-email-jszhang@marvell.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
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@marvell.com> 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@vger.kernel.org > 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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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,
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@marvell.com> --- drivers/pci/host/pcie-designware.c | 6 ++++++ 1 file changed, 6 insertions(+)