From mboxrd@z Thu Jan 1 00:00:00 1970 From: thierry.reding@gmail.com (Thierry Reding) Date: Tue, 23 Sep 2014 17:04:08 +0200 Subject: [PATCH v4] ARM: fix debug prints relevant to PCI devices In-Reply-To: <20140923140635.GR5182@n2100.arm.linux.org.uk> References: <1410085687-11273-1-git-send-email-vidyas@nvidia.com> <20140923140635.GR5182@n2100.arm.linux.org.uk> Message-ID: <20140923150407.GJ5982@ulmo> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 819 bytes Desc: not available URL: