Hello, I have been playing with a octeon3 (MIPS64r2 ITUS Shield) box I got the other day and I seem to almost have the vanilla kernel going. The vendor SDK has a 3.10.20-rt14 kernel with apparently a fair stack of patches, I can recompile their kernel and it boots ok. I of course would be happier with a vanilla kernel so I have been trying to get 4.3 up. To me it looks like most of the patches they had have already been unstreamed. 4.3 boots and seems to get to pci bus initialization before dying. The documentation I googled up seems to be talking about the new pci stuff for 2.6 and I have been getting hits from 2009 and 2011 which seem to be when the first Octeon processors were being ported. Specifically I think my problem is in this part of the boot log Enabling Octeon big bar support PCI Status: PCI 64-bit vgaarb: loaded SCSI subsystem initialized PCI host bridge to bus 0000:00 pci_bus 0000:00: root bus resource [mem 0x11b00f0000000-0x11b0130000000] (bus address [0xf0000000-0x130000000]) pci_bus 0000:00: root bus resource [io 0x4000-0xffffffff] pci_bus 0000:00: root bus resource [??? 0x00000000 flags 0x0] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff] Data bus error, epc == ffffffff8148fb20, ra == ffffffff813c8750 Oops[#1]: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.3.0 #2 task: 800000004ec52c08 ti: 800000004ec54000 task.ti: 800000004ec54000 $ 0 : 0000000000000000 0000000014109ce1 8001190400000000 0000000000000001 $ 4 : 0000000000000000 0000000000000000 0000000000000000 0000000000000004 $ 8 : 800000004ec57bc0 ffffffff8174c1c8 ffffffff817c0000 ffffffff81740000 $12 : 0000000000000020 ffffffff8139b66c ffffffff817c0000 0000000000000000 $16 : 800000004ee09400 800000004ec57c50 ffffffff827d0000 0000000000000001 $20 : 0000000000000000 ffffffff817692a0 0000000000000000 ffffffff81797758 $24 : ffffffffffffffff ffffffff8116e438 $28 : 800000004ec54000 800000004ec57bc0 ffffffff817b0000 ffffffff813c8750 Hi : 0000000000000000 Lo : 08d4a84676000000 epc : ffffffff8148fb20 octeon_read_config+0x60/0x90 ra : ffffffff813c8750 pci_bus_read_config_dword+0x88/0xc0 Status: 14109ce2 KX SX UX KERNEL EXL Cause : 4080801c (ExcCode 07) PrId : 000d9602 (Cavium Octeon III) Modules linked in: Process swapper/0 (pid: 1, threadinfo=800000004ec54000, task=800000004ec52c08, t Stack : 0000000000000001 ffffffff81166f24 0000000000000000 0000000000000000 ffffffff8174c550 0000000000000000 800000004ec57c50 000000000000ea60 800000004ee09400 ffffffff813cabc0 0000000000000000 0000000000000000 800000004ee09400 0000000000000000 0000000000000000 ffffffff817692a0 ffffffff816f56d8 ffffffff813cc494 800000004ec57c78 ffffffff815cf3f0 800000004ed9c320 0000000000000000 800000004ee09400 0000000000000100 0000000000000000 ffffffff813cc594 ffffffff817c0000 0000000000000000 800000004ee09400 0000000000000100 0000000000000000 ffffffff813cd66c ffffffff8174c1c8 800000004ee09400 0000000000000000 0000000000000000 0000000000000000 0000000000000000 ffffffff817692a0 ffffffff813cd984 ... Call Trace: [<ffffffff8148fb20>] octeon_read_config+0x60/0x90 [<ffffffff813c8750>] pci_bus_read_config_dword+0x88/0xc0 [<ffffffff813cabc0>] pci_bus_read_dev_vendor_id+0x40/0x180 [<ffffffff813cc494>] pci_scan_single_device+0x6c/0x100 [<ffffffff813cc594>] pci_scan_slot+0x6c/0x140 [<ffffffff813cd66c>] pci_scan_child_bus+0x3c/0x100 [<ffffffff813cd984>] pci_scan_root_bus_msi+0xbc/0xe8 [<ffffffff8148f568>] pcibios_scanbus+0x98/0x168 [<ffffffff817899ec>] pcibios_init+0x5c/0x98 [<ffffffff81100530>] do_one_initcall+0x98/0x1b8 [<ffffffff81769cec>] kernel_init_freeable+0x168/0x23c [<ffffffff815c9ddc>] kernel_init+0x14/0x110 [<ffffffff8111d8ac>] ret_from_kernel_thread+0x14/0x1c I am especially suspicious of the line pci_bus 0000:00: root bus resource [??? 0x00000000 flags 0x0] where it has not selected either memory or io space Is there a more proper place to ask this sort of question? I did look at https://www.linux-mips.org/wiki/PCI_Subsystem but it seems quite dated. The section -- PCI startup sequence (line 4) starts with "somewhere inside of pcibios_init" which seems to be where 4.3 is crashing but does not expand on it very much. I am sort of familiar with how PCI works on x86 with config space & BARs and have written userspace and kernel drivers, but I usually let Linux configure the BARs for me. Is there something I should be studying up on? Thank you, Jim McMechan
