On Wed, Nov 29, 2017 at 11:01:33AM -0600, Bjorn Helgaas wrote: > [+cc Lorenzo] > > On Sun, Nov 26, 2017 at 01:02:09AM +0530, Manikanta Maddireddy wrote: > > pci_flags variable is used in inline functions in 'pci.h', Tegra PCIe > > driver use one of these functions pci_add_flags() and includes 'pci.h'. > > Export pci_flags to allow Tegra PCIe host controller driver to be > > compiled as loadable kernel module. > > Here's the usage in tegra_pcie_probe(): > > pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS); > > We've probably had this discussion before, but I don't know why Tegra > needs PCI_REASSIGN_ALL_RSRC and PCI_REASSIGN_ALL_BUS. > > I would prefer to drop this usage of pci_add_flags() if possible. It > seems to be just an arm/powerpc thing and I'm not convinced it's > really necessary. It is hard to say if it is really necessary (because it depends on firmware configuration - ie pci_scan_bridge()), that's the problem. I suspect it can trigger regressions if we do not set it (since it affects what pcibios_assign_all_busses() returns on eg arm/arm64). There are two things we can do: 1) Set it unconditionally in arch code (in a hook to be defined) 2) We remove it on a per-host bridge basis and ask for testing I agree this may have trickled from host bridge to host bridge through copy'n'paste and it is not based on any firmware assumtpion but I can't say if it is really needed. Lorenzo -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
