Re: [PATCH V1 1/2] PCI: thunder: Enable ACPI PCI controller for ThunderX pass2.x silicon version

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, Dec 01, 2016 at 02:54:50PM +0000, Lorenzo Pieralisi wrote:
> On Thu, Dec 01, 2016 at 02:55:49PM +0100, Robert Richter wrote:
> > Tomasz, Bjorn,
> > 
> > On 01.12.16 09:49:51, Tomasz Nowicki wrote:
> > > I put the picture together here (on top of your pci/ecam branch):
> > > [1] https://github.com/semihalf-nowicki-tomasz/linux/commits/pci-quirks-thunderx-v2
> > 
> > please note that acpi_* functions must be protected with acpi_disabled
> > or something else to make sure an acpi enabled kernel does not break
> > dt. See the crash below with above branch.
> 
> You could use struct device.of_node, or just move the MCFG check to ACPI
> code that probes the root bus in arm64 before calling pci_ecam_create()
> which will save you some ifdeffery too while at it.

Oh, I like that idea even better!  I took the acpi_disabled check back out
of acpi_resource_consumer() and moved the call to
pci_acpi_setup_ecam_mapping().  Thanks!

> > [   12.493028] Unable to handle kernel NULL pointer dereference at virtual address 00000018
> > [   12.501113] pgd = ffff0000090a0000
> > [   12.504511] [00000018] *pgd=0000010fffef0003[   12.508602] , *pud=0000010fffef0003
> > , *pmd=0000010fffee0003[   12.514093] , *pte=0000000000000000
> > [   12.517575]
> > [   12.519064] Internal error: Oops: 96000005 [#1] SMP
> > [   12.523933] Modules linked in:
> > [   12.526987] CPU: 73 PID: 1 Comm: swapper/0 Tainted: G        W       4.9.0-rc6.0.vanilla10-00019-g09abd2b6bbeb #135
> > [   12.537409] Hardware name: Cavium ThunderX CRB/To be filled by O.E.M., BIOS 5.11 12/12/2012
> > [   12.545748] task: ffff800fe85b8000 task.stack: ffff800ff4288000
> > [   12.551674] PC is at acpi_ns_walk_namespace+0x68/0x1d4
> > [   12.556803] LR is at acpi_get_devices+0x6c/0x94
> > ...
> > [   13.124920] [<ffff0000084dc5a0>] acpi_ns_walk_namespace+0x68/0x1d4
> > [   13.131090] [<ffff0000084dcadc>] acpi_get_devices+0x6c/0x94
> > [   13.136663] [<ffff0000084c0aec>] acpi_resource_consumer+0x34/0x44
> > [   13.142752] [<ffff000008496bc0>] pci_ecam_create+0x80/0x228
> > [   13.148314] [<ffff000008498e64>] pci_host_common_probe+0x294/0x348
> > [   13.154486] [<ffff00000849bf3c>] thunder_ecam_probe+0x2c/0x38
> > [   13.160226] [<ffff0000085880b8>] platform_drv_probe+0x60/0xc8
> > [   13.165970] [<ffff000008585a04>] driver_probe_device+0x26c/0x420
> > [   13.171966] [<ffff000008585cdc>] __driver_attach+0x124/0x128
> > [   13.177615] [<ffff000008583238>] bus_for_each_dev+0x70/0xb0
> > [   13.183177] [<ffff000008585060>] driver_attach+0x30/0x40
> > [   13.188478] [<ffff000008584a98>] bus_add_driver+0x200/0x2b8
> > [   13.194041] [<ffff000008586860>] driver_register+0x68/0x100
> > [   13.199602] [<ffff000008587fdc>] __platform_driver_register+0x54/0x60
> > [   13.206038] [<ffff000008c39b98>] thunder_ecam_driver_init+0x18/0x20
> > [   13.212296] [<ffff000008082d94>] do_one_initcall+0x44/0x138
> > [   13.217862] [<ffff000008c00d0c>] kernel_init_freeable+0x1ac/0x24c
> > [   13.223950] [<ffff0000088605f0>] kernel_init+0x18/0x110
> > [   13.229165] [<ffff000008082b30>] ret_from_fork+0x10/0x20