Thread (5 messages) flat view 5 messages, 3 authors, 2021-06-03

Re: Arm64 double PCI ECAM reservations in acpi_resource_consumer()

From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2021-06-02 22:13:19
Also in: linux-pci

[+cc linux-pci]

On Wed, Jun 2, 2021 at 4:49 PM Qian Cai [off-list ref] wrote:
Bjorn, I noticed PCI ECAM could be reserved twice on arm64. Firs time through,

[   19.087790][    T1]  acpi_ns_walk_namespace+0xc0/0x390
[   19.092927][    T1]  acpi_get_devices+0x160/0x1a4
[   19.097629][    T1]  acpi_resource_consumer+0x8c/0xc0
[   19.102680][    T1]  pci_acpi_scan_root+0x158/0x4c8
[   19.107555][    T1]  acpi_pci_root_add+0x450/0x8e8
[   19.112345][    T1]  acpi_bus_attach+0x300/0x7d0
[   19.116960][    T1]  acpi_bus_attach+0x178/0x7d0
[   19.121576][    T1]  acpi_bus_attach+0x178/0x7d0
[   19.126190][    T1]  acpi_bus_scan+0xa8/0x170
[   19.130545][    T1]  acpi_scan_init+0x220/0x558
[   19.135074][    T1]  acpi_init+0x1f4/0x270

where pci_acpi_setup_ecam_mapping() confirmed all reservations are succeed. Then,

[   19.880588][    T1]  acpi_ns_walk_namespace+0xc0/0x390
[   19.885725][    T1]  acpi_get_devices+0x160/0x1a4
[   19.890426][    T1]  pnpacpi_init+0xa0/0x10

As the results, those messages are showed up during the boot in pnpacpi_init().

[ 17.763968] system 00:00: [mem 0x10000000000-0x1000fffffff window] could not be reserved
[ 17.772900] system 00:00: [mem 0x7800000000-0x780fffffff window] could not be reserved
[ 17.781627] system 00:00: [mem 0x7000000000-0x700fffffff window] could not be reserved
[ 17.790350] system 00:00: [mem 0x6000000000-0x600fffffff window] could not be reserved
[ 17.799073] system 00:00: [mem 0x5800000000-0x580fffffff window] could not be reserved
[ 17.808155] system 00:00: [mem 0x1000000000-0x100fffffff window] could not be reserved
[ 17.816862] system 00:00: [mem 0x600000000-0x60fffffff window] could not be reserved
[ 17.825417] system 00:00: [mem 0x400000000-0x40fffffff window] could not be reserved

Looking through the x86's version of pci_acpi_scan_root(), it won't call acpi_resource_consumer(), so I suppose this bug is only affecting arm64?
This might be related to
https://lore.kernel.org/linux-acpi/20210510234020.1330087-1-luzmaximilian@gmail.com/T/#u (local)

Can you try applying that patch to see if it is related?

Bjorn

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help