Re: [PATCH v1 2/2] MIPS: PCI: Remove unused busn_offset
From: Joshua Kinard <hidden>
Date: 2017-06-11 01:14:40
Also in:
linux-pci, lkml
On 05/19/2017 15:56, Bjorn Helgaas wrote:
quoted hunk ↗ jump to hunk
pci_add_resource_offset() is for host bridge windows where the bridge translates CPU addresses to PCI bus addresses by adding an offset. To my knowledge, no host bridge translates bus numbers, so this is only useful for MEM and IO windows. In any event, host->busn_offset is never set to anything other than zero, so pci_add_resource() is sufficient. a2e50f53d535 ("MIPS: PCI: Add a hook for IORESOURCE_BUS in pci_controller/bridge_controller") also added busn_resource itself. This is currently unused but may be used by future SGI IP27 fixes, so I left it there. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Joshua Kinard <redacted> --- arch/mips/include/asm/pci.h | 1 - arch/mips/pci/pci-legacy.c | 3 +-- 2 files changed, 1 insertion(+), 3 deletions(-)diff --git a/arch/mips/include/asm/pci.h b/arch/mips/include/asm/pci.h index 1000c1b4c875..52f551ee492d 100644 --- a/arch/mips/include/asm/pci.h +++ b/arch/mips/include/asm/pci.h@@ -39,7 +39,6 @@ struct pci_controller { unsigned long io_offset; unsigned long io_map_base; struct resource *busn_resource; - unsigned long busn_offset; #ifndef CONFIG_PCI_DOMAINS_GENERIC unsigned int index;diff --git a/arch/mips/pci/pci-legacy.c b/arch/mips/pci/pci-legacy.c index 3a84f6c0c840..174575a9a112 100644 --- a/arch/mips/pci/pci-legacy.c +++ b/arch/mips/pci/pci-legacy.c@@ -86,8 +86,7 @@ static void pcibios_scanbus(struct pci_controller *hose) hose->mem_resource, hose->mem_offset); pci_add_resource_offset(&resources, hose->io_resource, hose->io_offset); - pci_add_resource_offset(&resources, - hose->busn_resource, hose->busn_offset); + pci_add_resource(&resources, hose->busn_resource); bus = pci_scan_root_bus(NULL, next_busno, hose->pci_ops, hose, &resources); hose->bus = bus;
I tested this change out on my Octane (SGI-IP30) and Origin 200 (SGI-IP27), and it appears to work fine on both systems (for now). The Octane has two PCI host bridges in it right now (BaseIO & PCI Card cage), while the Origin 200 only has one. Haven't tested it on my bigger Onyx2 w/ multiple host bridges, but that machine has other problems, so I am ignoring it for now. I wasn't aware that pci_add_resource existed back when I wrote the patch. The symptom that was addressed was some conditional in the PCI core -- I forget where -- wasn't enumerating multiple PCI busses without having an IORESOURCE_BUS struct passed to it. I think it found the first bus and then moved on to other subsystems, which usually led to a non-booting machine. Acked-by: Joshua Kinard <redacted>