On Monday 17 June 2013 18:45:52 Jingoo Han wrote: > On Friday, June 14, 2013 9:54 PM, Arnd Bergmann wrote: > > > > Please look up the documentation about inbound viewport and describe > > in a code comment what it does. I /assume/ that this is how DMA accesses > > from the bus get translated into AXI bus transactions. If so, you have > > to let the window translate addresses from RAM. If it's something else, > > then you should document what it is and how it needs to be set up. > > One of our hardware engineer confirmed it. > He said that these inbound functions are unnecessary. > Also, I checked that PCIe works properly without these functions. > So, I will remove these inbound functions. Ok, good. So DMA just gets translated 1:1 independent of the inbound viewport? Have you tested this with PCI device using DMA? > static int exynos_pcie_setup(int nr, struct pci_sys_data *sys) > { > struct pcie_port *pp; > > pp = sys_to_pcie(sys); > > if (!pp) > return 0; > > if (global_io_offset < SZ_1M && pp->config.io_size > 0) { > sys->io_offset = global_io_offset - pp->config.io_bus_addr; /* normally 0 */ > pci_ioremap_io(sys->io_offset, pp->io.start); > global_io_offset += SZ_64K; > } > > sys->mem_offset = pp->mem.start - pp->config.mem_bus_addr; /* normally 0 */ > > pci_add_resource_offset(&sys->resources, &pp->io, sys->io_offset); > pci_add_resource_offset(&sys->resources, &pp->mem, sys->mem_offset); > > return 1; > } This is what I meant, yes. > In this case, boot message is as below: > > PCI host bridge to bus 0000:00 > pci_bus 0000:00: root bus resource [io 0x40001000-0x40010fff] > pci_bus 0000:00: root bus resource [mem 0x40011000-0x5fffffff] > pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff] > pci 0000:00:00.0: [144d:a549] type 01 class 0x060400 > [.....] > PCI host bridge to bus 0001:00 > pci_bus 0001:00: root bus resource [io 0x60001000-0x60010fff] (bus address [0x5fff1000-0x6000 > 0fff]) > pci_bus 0001:00: root bus resource [mem 0x60011000-0x7fffffff] > pci_bus 0001:00: No busn resource found for root bus, will use [bus 00-ff] > pci 0001:00:00.0: [144d:a549] type 01 class 0x060400 The io resources here look wrong. I would have expected pci_bus 0000:00: root bus resource [io 0x001000-0x00ffff] pci_bus 0001:00: root bus resource [io 0x010000-0x01ffff] (bus address [0x000000-0x00ffff]) Please have a look at the pci-mvebu driver and how it calculates its 'realio' resource. > > > > > +static int __exit exynos_pcie_remove(struct platform_device *pdev) > > > > > +{ > > > > > + struct pcie_port *pp = platform_get_drvdata(pdev); > > > > > + > > > > > + clk_disable_unprepare(pp->bus_clk); > > > > > + clk_disable_unprepare(pp->clk); > > > > > + > > > > > + return 0; > > > > > +} > > > > > > > > You also don't remove the PCI devices here, as mentioned in an earlier > > > > review. > > > > > > I reviewed Marvell PCIe driver and Tegra PCIe driver; however, > > > I cannot know what you mean. > > > > > > Could let me know which additional functions are needed? > > > > The mvebu driver does not allow module unload. I haven't looked at the > > tegra driver. If you allow unloading the driver and provide a 'remove' > > callback, that callback needs to clean up the entire bus and remove > > all child devices that were added as well as undo everything the > > probe function did. I think it would be great if you can do that, although > > it might not be easy. The simplest solution would be to not support > > unloading though. > > As the mvebu driver uses platform_driver_probe(), the Exynos driver uses > platform_driver_probe(). Thus, I will not provide a 'remove' callback. Well, the important part is not to provide a module_exit() function, which will ensure the driver cannot be unloaded. Arnd -- 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