Re: ACPI regression? Was Re: Ethernet chip disappeared from lspci

Jiang Liu
2015-06-21T17:55:55Z

On 2015/6/22 1:25, Jiang Liu wrote:
[...]
>>>> - Memory behind bridge: 80000000-801fffff
>>>> - Prefetchable memory behind bridge: 0000000080200000-00000000803fffff
>>>> + Memory behind bridge: ff000000-ff1fffff
>>>> + Prefetchable memory behind bridge: 00000000ff200000-00000000ff3fffff
>>>>
>>>> Can't this cause a problem? E.g. programming the bridge with an address range
>>>> that the bridge doesn't actually support?
>>> This worked in v3.18.16, but not in v4.0.5 or v4.1.0-rc8. You
>>> attached a v4.1.0-rc8 dmesg log earlier. Would you mind collecting a
>>> v3.18.16 dmesg log, so we can compare them?
>>
>> I collected all 3 for you to compare them, compressed, attached.
>>
>> BTW, I browsed git log and found 2ea3d266bab3b497238113b20136f7c3f69ad9c0
>> as suspicious. I will try the 4.0/4.1 kernels with this one reverted.
>>
>>>
>>> These (from the v4.1.0-rc8 dmesg) look wrong, but I'll have to look at
>>> the code to see what might be going on:
>>>
>>> acpi PNP0A08:00: host bridge window expanded to [mem
>>> 0x00000000-0xffffffff window]; [mem 0x00000000-0xffffffff window]
>>> ignored
>>> pci 0000:00:1c.1: can't claim BAR 15 [mem 0xfdf00000-0xfdffffff
>>> 64bit pref]: address conflict with PCI Bus 0000:00 [mem
>>> 0xf0000000-0xfed8ffff window]
>>>
>>> Bjorn
> Hi Bjorn and Boszormenyi,
> From the 3.18 kernel, we got a message:
> [ 0.126248] acpi PNP0A08:00: host bridge window
> [0x400000000-0xfffffffff] (ignored, not CPU addressable)
> And from 4.1.-rc8, we got another message:
> [ 0.127051] acpi PNP0A08:00: host bridge window expanded to [mem
> 0x00000000-0xffffffff window]; [mem 0x00000000-0xffffffff window] ignored
>
> That smells like a 32bit overflow or 64bit cut-off issue.
Hi Bjorn and Boszormenyi,
With v3.18.6, it uses u64 to compare resource ranges. We changed to use
resource_size_t with recent changes, and resource_size_t
may be u32 or u64 depending on configuration. So resource range
[0x400000000-0xfffffffff] may have been cut-off as
[0x00000000-0xffffffff], thus cause the trouble.

Hi Boszormenyi,
Could you please help to try following test patch?
against v4.1-rc8?
Thanks!
Gerry
-------------------------------------------------------------------
diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 8244f013f210..d7b8c392c420 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -206,6 +206,11 @@ static bool acpi_decode_space(struct resource_win *win,

res->start = attr->minimum;
res->end = attr->maximum;
+ if (res->start != attr->minimum || res->end != attr->maximum) {
+ pr_warn("resource window ([%#llx-%#llx] ignored, not CPU
addressable)\n",
+ attr->minimum, attr->maximum);
+ return false;
+ }

/*
* For bridges that translate addresses across the bridge,
-----------------------------------------------------------------------------