On Wed, Jun 02, 2021 at 08:15:20PM -0400, Qian Cai wrote: > > > On 6/2/2021 6:09 PM, Bjorn Helgaas wrote: > > [+cc linux-pci] > > > > On Wed, Jun 2, 2021 at 4:49 PM Qian Cai <quic_qiancai@xxxxxxxxxxx> 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@xxxxxxxxx/T/#u > > > > Can you try applying that patch to see if it is related? > > Unfortunately, that revert patch does not help. FYI, here is the first reservation from acpi_resource_consumer(). This is not the "reservation". AFAICS acpi_resource_consumer() checks whether the ECAM region is part of _a_ given ACPI device _CRS in the namespace, it does not "reserve" anything. IIUC the issue here is that we request the ECAM region in pci_ecam_create() and later the code in: drivers/pnp/system.c tries to request the ECAM region (that lives in the PNP0C02 _CRS) and fails (see reserve_range() and request_mem_region()). As the comment in reserve_range() goes, this is harmless, not sure whether there is anything to do about it. Lorenzo > [ 16.224306] acpi PNP0A08:00: ECAM area [mem 0x10000000000-0x1000fffffff] reserved by PNP0C02:00 > [ 16.241027] acpi PNP0A08:00: ECAM at [mem 0x10000000000-0x1000fffffff] for [bus 00-ff] > [ 16.810172] acpi PNP0A08:01: ECAM area [mem 0x7800000000-0x780fffffff] reserved by PNP0C02:00 > [ 16.826701] acpi PNP0A08:01: ECAM at [mem 0x7800000000-0x780fffffff] for [bus 00-ff] > [ 17.289302] acpi PNP0A08:02: ECAM area [mem 0x1000000000-0x100fffffff] reserved by PNP0C02:00 > [ 17.305840] acpi PNP0A08:02: ECAM at [mem 0x1000000000-0x100fffffff] for [bus 00-ff] > [ 17.641917] acpi PNP0A08:03: ECAM area [mem 0x5800000000-0x580fffffff] reserved by PNP0C02:00 > [ 17.658445] acpi PNP0A08:03: ECAM at [mem 0x5800000000-0x580fffffff] for [bus 00-ff] > [ 18.059837] acpi PNP0A08:04: ECAM area [mem 0x6000000000-0x600fffffff] reserved by PNP0C02:00 > [ 18.076368] acpi PNP0A08:04: ECAM at [mem 0x6000000000-0x600fffffff] for [bus 00-ff] > [ 18.413220] acpi PNP0A08:05: ECAM area [mem 0x7000000000-0x700fffffff] reserved by PNP0C02:00 > [ 18.429745] acpi PNP0A08:05: ECAM at [mem 0x7000000000-0x700fffffff] for [bus 00-ff] > [ 18.767189] acpi PNP0A08:06: ECAM area [mem 0x600000000-0x60fffffff] reserved by PNP0C02:00 > [ 18.783559] acpi PNP0A08:06: ECAM at [mem 0x600000000-0x60fffffff] for [bus 00-ff] > [ 19.201613] acpi PNP0A08:07: ECAM area [mem 0x400000000-0x40fffffff] reserved by PNP0C02:00 > [ 19.217965] acpi PNP0A08:07: ECAM at [mem 0x400000000-0x40fffffff] for [bus 00-ff]
