On 06/12/2013 06:30 AM, Thierry Reding wrote: > On Mon, Apr 15, 2013 at 12:28:12PM -0600, Stephen Warren wrote: >> On 04/03/2013 08:45 AM, Thierry Reding wrote: >>> Move the PCIe driver from arch/arm/mach-tegra into the >>> drivers/pci/host directory. The motivation is to collect >>> various host controller drivers in the same location in order >>> to facilitate refactoring. >>> >>> The Tegra PCIe driver has been largely rewritten, both in order >>> to turn it into a proper platform driver and to add MSI (based >>> on code by Krishna Kishore <kthota@xxxxxxxxxx>) as well as >>> device tree support. ... >>> +static irqreturn_t tegra_pcie_msi_irq(int irq, void *data) >> ... >>> + return IRQ_HANDLED; >> >> Shouldn't this function return IRQ_NONE if no MSI status bits >> were found set? > > The IRQ isn't marked IRQF_SHARED, so I don't think this is needed. Isn't it still useful to detect unexpected/stuck interrupts? >>> +static int tegra_pcie_enable(struct tegra_pcie *pcie) ... >> >> Why is that needed; when would a port get enabled if it was >> already enabled, and if it was already enabled, wouldn't you want >> this function to be a no-op rather than destroying everything and >> starting again? > > I'm not sure I understand what you're saying. The intent of this > function is to enable a port, check that there's a link and disable > the port otherwise. That way we don't keep ports around where > nothing is connected. Hmm. I have no idea either now:-( The body of tegra_pcie_enable() looks fine. >>> +static int tegra_pcie_probe(struct platform_device *pdev) >> ... >>> + pcibios_min_mem = 0; >> >> What does that mean/do? I wonder if that should be set to >> 0x80000000 by the Tegra30 patches? > > ARM defines PCIBIOS_MIN_MEM to that variable. That macro in turn is > only used by pci_bus_alloc_resource() AFAICT, which uses it to > override the start of a resource when allocating if res->start == > 0. As such it designates a lower-bound of valid PCI memory > addresses, so 0 on Tegra20 and 0x80000000 on Tegra30 don't seem > like good values. Maybe we need to set them to the lowest of the > prefetchable and non-prefetchable memory areas as defined in the > DT? > > It doesn't currently seem to matter at all, though, since we never > pass in a range that's 0, so the start address of resources can > never be 0 and therefore PCIBIOS_MIN_MEM is never used. Hmmm. I guess ignore it then. If the value won't ever be used, 0 is as good a value as any? -- 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
