On Tue, Sep 23, 2014 at 9:04 AM, Thierry Reding <thierry.red...@gmail.com> wrote: > On Tue, Sep 23, 2014 at 03:06:35PM +0100, Russell King - ARM Linux wrote: >> On Tue, Sep 23, 2014 at 07:56:01AM -0600, Bjorn Helgaas wrote: >> > This doesn't require any coordination with the PCI core, so I was just >> > leaving this up to the arch. But I guess I can at least give you my >> > opinion :) >> >> However, PCI core people have more knowledge of the issues here than I do. >> >> > > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c >> > > index 17a26c1..03c56ba 100644 >> > > --- a/arch/arm/kernel/bios32.c >> > > +++ b/arch/arm/kernel/bios32.c >> > > @@ -290,6 +290,7 @@ void pcibios_fixup_bus(struct pci_bus *bus) >> > > { >> > > struct pci_dev *dev; >> > > u16 features = PCI_COMMAND_SERR | PCI_COMMAND_PARITY | >> > > PCI_COMMAND_FAST_BACK; >> > > + bool has_pcie_dev = false; >> > > >> > > /* >> > > * Walk the devices on this bus, working out what we can >> > > @@ -298,6 +299,8 @@ void pcibios_fixup_bus(struct pci_bus *bus) >> > > list_for_each_entry(dev, &bus->devices, bus_list) { >> > > u16 status; >> > > >> > > + if (!has_pcie_dev) >> > > + has_pcie_dev = pci_is_pcie(dev); >> > > pci_read_config_word(dev, PCI_STATUS, &status); >> > > >> > > /* >> > > @@ -354,9 +357,11 @@ void pcibios_fixup_bus(struct pci_bus *bus) >> > > >> > > /* >> > > * Report what we did for this bus >> > > + * (only if the bus doesn't have any PCIe devices) >> > > */ >> > > - printk(KERN_INFO "PCI: bus%d: Fast back to back transfers >> > > %sabled\n", >> > > - bus->number, (features & PCI_COMMAND_FAST_BACK) ? "en" : >> > > "dis"); >> > > + if (!has_pcie_dev) >> > > + pr_info("PCI: bus%d: Fast back to back transfers >> > > %sabled\n", >> > > + bus->number, (features & PCI_COMMAND_FAST_BACK) >> > > ? "en" : "dis"); >> > >> > My first choice would be to just drop the printk altogether. >> >> It can be useful information. >> >> > If we want to keep the printk, it should be enough to test "bus->self >> > && !pci_is_pcie(bus->self)" to see whether Fast Back-to-Back can be >> > enabled. >> >> This is exactly the kind of issue that needs to be picked up by core >> PCI people. > > I agree. Wouldn't it be more useful to move this into the core? > Disabling fast back-to-back transfers hardly seems like an ARM- > specific "fixup" to me.
I would definitely support moving this into the core. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/