Re: Supermicro X9SRL-F - channel enumeration error & ACPI/firmware bug question

Bjorn Helgaas
2012-11-27T00:57:13Z

[+cc Dan]

On Mon, Nov 26, 2012 at 2:42 PM, Bruno Prémont
<bonbons@linux-vserver.org> wrote:
> Hi Justin,
>
> On Sat, 24 November 2012 "Justin Piszcz" wrote:
>> Is the following normal on an X9SRL-F board (bios 1.0a)?
>>
>> In the manual it states:
>>
>> Data Direct I/O
>> Select Enabled to enable Intel I/OAT (I/O Acceleration Technology), which
>> significantly reduces CPU overhead by leveraging CPU architectural
>> improvements and freeing the system resource for other tasks. The options
>> are Disabled and Enabled.
>>
>> Default is Enabled.
>>
>> When enabled in the kernel, I see the following:
>>
>> [ 0.696357] ioatdma: Intel(R) QuickData Technology Driver 4.00
>> [ 0.696487] ioatdma 0000:00:04.0: channel error register unreachable
>> [ 0.696546] ioatdma 0000:00:04.0: channel enumeration error
>> [ 0.696604] ioatdma 0000:00:04.0: Intel(R) I/OAT DMA Engine init failed
>> [ 0.696721] ioatdma 0000:00:04.1: channel error register unreachable
>> [ 0.696779] ioatdma 0000:00:04.1: channel enumeration error
>> [ 0.697522] ioatdma 0000:00:04.1: Intel(R) I/OAT DMA Engine init failed
>> [ 0.697617] ioatdma 0000:00:04.2: channel error register unreachable
>> [ 0.697681] ioatdma 0000:00:04.2: channel enumeration error
>> [ 0.697739] ioatdma 0000:00:04.2: Intel(R) I/OAT DMA Engine init failed
>> [ 0.697831] ioatdma 0000:00:04.3: channel error register unreachable
>> [ 0.697890] ioatdma 0000:00:04.3: channel enumeration error
>> [ 0.697948] ioatdma 0000:00:04.3: Intel(R) I/OAT DMA Engine init failed
>> [ 0.698037] ioatdma 0000:00:04.4: channel error register unreachable
>> [ 0.698095] ioatdma 0000:00:04.4: channel enumeration error
>> [ 0.698153] ioatdma 0000:00:04.4: Intel(R) I/OAT DMA Engine init failed
>> [ 0.698245] ioatdma 0000:00:04.5: channel error register unreachable
>> [ 0.698303] ioatdma 0000:00:04.5: channel enumeration error
>> [ 0.698360] ioatdma 0000:00:04.5: Intel(R) I/OAT DMA Engine init failed
>> [ 0.698449] ioatdma 0000:00:04.6: channel error register unreachable
>> [ 0.698508] ioatdma 0000:00:04.6: channel enumeration error
>> [ 0.698565] ioatdma 0000:00:04.6: Intel(R) I/OAT DMA Engine init failed
>> [ 0.698676] ioatdma 0000:00:04.7: channel error register unreachable
>> [ 0.698735] ioatdma 0000:00:04.7: channel enumeration error
>> [ 0.698792] ioatdma 0000:00:04.7: Intel(R) I/OAT DMA Engine init failed
>>
>> --
>>
>> Also, I tried using ASPM (enabled in BIOS), but since ACPI Linux query is
>> ignored, it fails to work:
>> [ 0.562229] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored
>>
>> I assume this is something Supermicro has to fix?
>
> You are probably missing some kernel config option(s) :) - I did fight similar
> issues on a Fujitsu SandyBridge Xeon based server.
>
> Check if enabling CONFIG_X86_X2APIC helps as well as other APIC/IOMMU options.

Changing config options is not a valid fix for error messages like
this. We should be able to make the config smarter by adding
dependencies or something, or else make the driver smart enough to
give a more useful diagnostic.

The "channel error register unreachable" message indicates that
pci_read_config_dword() failed. The register in question
(IOAT_PCI_CHANERR_INT_OFFSET) is at 0x180, so possibly we don't have
PCI config accessors for the extended config space (0x100-0xfff). A
complete dmesg log should show that.