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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Nov 22, 2018 at 04:53:54PM +0800, Hanjie Lin wrote: [...] > +static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size, > + u32 *val) > +{ > + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); > + > + /* > + * there is a bug of MESON AXG pcie controller that software can not > + * programe PCI_CLASS_DEVICE register, so we must return a fake right > + * value to ensure driver could probe successfully. > + */ > + if (where == PCI_CLASS_REVISION) { > + *val = readl(pci->dbi_base + PCI_CLASS_REVISION); > + /* keep revision id */ > + *val &= PCI_CLASS_REVISION_MASK; > + *val |= PCI_CLASS_BRIDGE_PCI << 16; > + return PCIBIOS_SUCCESSFUL; > + } As I said before, this looks broken. If this code (or other drivers with the same broken assumptions, eg dwc/pcie-qcom.c) carries out a, say, byte sized config access of eg PCI_CLASS_DEVICE you will get junk out of it according to your comment above. I would like to pick Bjorn's brain on this to see what we can really do to fix this (and other) drivers. Thanks, Lorenzo > + return dw_pcie_read(pci->dbi_base + where, size, val); > +} > + > +static int meson_pcie_wr_own_conf(struct pcie_port *pp, int where, > + int size, u32 val) > +{ > + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); > + > + return dw_pcie_write(pci->dbi_base + where, size, val); > +} > + > +static int meson_pcie_link_up(struct dw_pcie *pci) > +{ > + struct meson_pcie *mp = to_meson_pcie(pci); > + struct device *dev = pci->dev; > + u32 smlh_up = 0; > + u32 ltssm_up = 0; > + u32 rdlh_up = 0; > + u32 speed_okay = 0; > + u32 cnt = 0; > + u32 state12, state17; > + > + while (smlh_up == 0 || rdlh_up == 0 || ltssm_up == 0 || > + speed_okay == 0) { > + udelay(20); > + > + state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12); > + state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17); > + smlh_up = IS_SMLH_LINK_UP(state12); > + rdlh_up = IS_RDLH_LINK_UP(state12); > + ltssm_up = IS_LTSSM_UP(state12); > + > + if (PM_CURRENT_STATE(state17) < PCIE_GEN3) > + speed_okay = 1; > + > + if (smlh_up) > + dev_dbg(dev, "smlh_link_up is on\n"); > + if (rdlh_up) > + dev_dbg(dev, "rdlh_link_up is on\n"); > + if (ltssm_up) > + dev_dbg(dev, "ltssm_up is on\n"); > + if (speed_okay) > + dev_dbg(dev, "speed_okay\n"); > + > + cnt++; > + > + if (cnt >= WAIT_LINKUP_TIMEOUT) { > + dev_err(dev, "Error: Wait linkup timeout.\n"); > + return 0; > + } > + } > + > + return 1; > +} > + > +static int meson_pcie_host_init(struct pcie_port *pp) > +{ > + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); > + struct meson_pcie *mp = to_meson_pcie(pci); > + int ret; > + > + ret = meson_pcie_establish_link(mp); > + if (ret) > + return ret; > + > + meson_pcie_enable_interrupts(mp); > + > + return 0; > +} > + > +static const struct dw_pcie_host_ops meson_pcie_host_ops = { > + .rd_own_conf = meson_pcie_rd_own_conf, > + .wr_own_conf = meson_pcie_wr_own_conf, > + .host_init = meson_pcie_host_init, > +}; > + > +static int meson_add_pcie_port(struct meson_pcie *mp, > + struct platform_device *pdev) > +{ > + struct dw_pcie *pci = &mp->pci; > + struct pcie_port *pp = &pci->pp; > + struct device *dev = &pdev->dev; > + int ret; > + > + if (IS_ENABLED(CONFIG_PCI_MSI)) { > + pp->msi_irq = platform_get_irq(pdev, 0); > + if (pp->msi_irq < 0) { > + dev_err(dev, "failed to get msi irq\n"); > + return pp->msi_irq; > + } > + } > + > + pp->ops = &meson_pcie_host_ops; > + pci->dbi_base = mp->mem_res.elbi_base; > + > + ret = dw_pcie_host_init(pp); > + if (ret) { > + dev_err(dev, "failed to initialize host\n"); > + return ret; > + } > + > + return 0; > +} > + > +static const struct dw_pcie_ops dw_pcie_ops = { > + .link_up = meson_pcie_link_up, > +}; > + > +static int meson_pcie_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct dw_pcie *pci; > + struct meson_pcie *mp; > + int ret; > + > + mp = devm_kzalloc(dev, sizeof(*mp), GFP_KERNEL); > + if (!mp) > + return -ENOMEM; > + > + pci = &mp->pci; > + pci->dev = dev; > + pci->ops = &dw_pcie_ops; > + > + mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); > + if (IS_ERR(mp->reset_gpio)) { > + dev_err(dev, "Get reset gpio failed\n"); > + return PTR_ERR(mp->reset_gpio); > + } > + > + ret = meson_pcie_get_resets(mp); > + if (ret) { > + dev_err(dev, "Get reset resource failed, %d\n", ret); > + return ret; > + } > + > + ret = meson_pcie_get_mems(pdev, mp); > + if (ret) { > + dev_err(dev, "Get memory resource failed, %d\n", ret); > + return ret; > + } > + > + meson_pcie_power_on(mp); > + meson_pcie_reset(mp); > + > + ret = meson_pcie_probe_clocks(mp); > + if (ret) { > + dev_err(dev, "Init clock resources failed, %d\n", ret); > + return ret; > + } > + > + platform_set_drvdata(pdev, mp); > + > + ret = meson_add_pcie_port(mp, pdev); > + if (ret < 0) { > + dev_err(dev, "Add PCIE port failed, %d\n", ret); > + return ret; > + } > + > + return 0; > +} > + > +static const struct of_device_id meson_pcie_of_match[] = { > + { > + .compatible = "amlogic,axg-pcie", > + }, > + {}, > +}; > + > +static struct platform_driver meson_pcie_driver = { > + .probe = meson_pcie_probe, > + .driver = { > + .name = "meson-pcie", > + .of_match_table = meson_pcie_of_match, > + }, > +}; > + > +builtin_platform_driver(meson_pcie_driver); > -- > 2.7.4 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel