Re: Abysmal HDD/USB write speed after sleep on a UEFI system

From: Artem S. Tashkinov
Date: Wed May 08 2013 - 04:31:39 EST


May 8, 2013 04:03:18 AM, Bjorn Helgaas wrote:
On Tue, May 7, 2013 at 2:48 PM, Patrik Jakobsson
> wrote:
>> On Tue, May 7, 2013 at 10:20 PM, Bjorn Helgaas
wrote:
>>>> I'm not sure if reading /proc/mtrr actually reads the registers out of
>>>> the CPU each time, or whether we just return the cached values we read
>>>> out during initial boot-up. If the latter, then this output isn't
>>>> really useful as there's no guarantee the values are still intact.
>>>
>>> Good point. From what I can tell, on Artem's system with "CPU0:
>>> Intel(R) Core(TM) i5-2500 CPU @ 3.30GHz," we would be using
>>> generic_mtrr_ops, and generic_get_mtrr() appears to read from the
>>> MSRs, so I think it should be useful.
>>
>> FWIW, that motherboard suffers from a PCI to PCIE bridge problem. It might
>> have been fixed by bios upgrades by now but not sure.
>>
>> It might also suffer (depending on the revision) from the Sandy bridge SATA
>> issue. So if affected, SATA controller is a ticking bomb.
>>
>> I have a P8H67-V motherboard but I haven't seen any suspend related issues.
>>
>> If this is totally unrelated I'm sorry for wasting your time. Just thought it
>> might be good to know.
>
>Thanks for chiming in. I'm not familiar with either of the issues you
>mentioned. Do you have any references where I could read up on them?
>
>Artem's system has a PCIe-to-PCI bridge (not a PCI-to-PCIe bridge) at
>05:00.0, but it leads to [bus 06] and there's nothing on bus 06, so I
>don't think that's the problem.
>
>And the issue affects both USB and a hard drive, so I suspect it's
>more than just SATA. Artem, did you identify the PCI devices leading
>to your USB and hard drive? I can't remember if I've actually seen
>that.

I posted my lspci information here https://bugzilla.kernel.org/show_bug.cgi?id=53551

If that's not enough, please tell how can I collect this information.

The SATA issue is discussed here: https://bugzilla.kernel.org/show_bug.cgi?id=43229

According to Intel and Linux kernel developers it poses no threat.

Best regards,

Artem
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