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Date:   Sun, 22 Apr 2018 12:48:49 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     "Alex G." <mr.nuke.me@gmail.com>
Cc:     linux-acpi@vger.kernel.org, linux-edac@vger.kernel.org,
        rjw@rjwysocki.net, lenb@kernel.org, tony.luck@intel.com,
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        Yazen Ghannam <yazen.ghannam@amd.com>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>
Subject: Re: [RFC PATCH v2 3/4] acpi: apei: Do not panic() when correctable
 errors are marked as fatal.
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On Thu, Apr 19, 2018 at 05:55:08PM -0500, Alex G. wrote:
> > How does such an error look like, in detail?
> 
> It's green on the soft side, with lots of red accents, as well as some
> textured white shades:
> 
> [   51.414616] pciehp 0000:b0:06.0:pcie204: Slot(176): Link Down
> [   51.414634] pciehp 0000:b0:05.0:pcie204: Slot(179): Link Down
> [   52.703343] FIRMWARE BUG: Firmware sent fatal error that we were able
> to correct
> [   52.703345] BROKEN FIRMWARE: Complain to your hardware vendor
> [   52.703347] {1}[Hardware Error]: Hardware error from APEI Generic
> Hardware Error Source: 1
> [   52.703358] pciehp 0000:b0:06.0:pcie204: Slot(176): Link Up
> [   52.711616] {1}[Hardware Error]: event severity: fatal
> [   52.716754] {1}[Hardware Error]:  Error 0, type: fatal
> [   52.721891] {1}[Hardware Error]:   section_type: PCIe error
> [   52.727463] {1}[Hardware Error]:   port_type: 6, downstream switch port
> [   52.734075] {1}[Hardware Error]:   version: 3.0
> [   52.738607] {1}[Hardware Error]:   command: 0x0407, status: 0x0010
> [   52.744786] {1}[Hardware Error]:   device_id: 0000:b0:06.0
> [   52.750271] {1}[Hardware Error]:   slot: 4
> [   52.754371] {1}[Hardware Error]:   secondary_bus: 0xb3
> [   52.759509] {1}[Hardware Error]:   vendor_id: 0x10b5, device_id: 0x9733
> [   52.766123] {1}[Hardware Error]:   class_code: 000406
> [   52.771182] {1}[Hardware Error]:   bridge: secondary_status: 0x0000,
> control: 0x0003
> [   52.779038] pcieport 0000:b0:06.0: aer_status: 0x00100000, aer_mask:
> 0x01a10000
> [   52.782303] nvme0n1: detected capacity change from 3200631791616 to 0
> [   52.786348] pcieport 0000:b0:06.0:    [20] Unsupported Request
> [   52.786349] pcieport 0000:b0:06.0: aer_layer=Transaction Layer,
> aer_agent=Requester ID
> [   52.786350] pcieport 0000:b0:06.0: aer_uncor_severity: 0x004eb030
> [   52.786352] pcieport 0000:b0:06.0:   TLP Header: 40000001 0000020f
> e12023bc 01000000
> [   52.786357] pcieport 0000:b0:06.0: broadcast error_detected message
> [   52.883895] pci 0000:b3:00.0: device has no driver
> [   52.883976] pciehp 0000:b0:06.0:pcie204: Slot(176): Link Down
> [   52.884184] pciehp 0000:b0:06.0:pcie204: Slot(176): Link Down event
> queued; currently getting powered on
> [   52.967175] pciehp 0000:b0:06.0:pcie204: Slot(176): Link Up

Btw, from another discussion we're having with Yazen:

@Yazen, do you see how this error record is worth shit?

 class_code: 000406
 command: 0x0407, status: 0x0010
 bridge: secondary_status: 0x0000, control: 0x0003
 aer_status: 0x00100000, aer_mask: 0x01a10000
 aer_uncor_severity: 0x004eb030

those above are only some of the fields which are purely useless
undecoded. Makes me wonder what's worse for the user: dump the
half-decoded error or not dump an error at all...

Anyway, Alex, I see this in the logs:

[   66.581121] pciehp 0000:b0:06.0:pcie204: Slot(176): Link Down
[   66.591939] pciehp 0000:b0:05.0:pcie204: Slot(179): Card not present
[   66.592102] pciehp 0000:b0:06.0:pcie204: Slot(176): Card not present

and that comes from that pciehp_isr() interrupt handler AFAICT.

So there *is* a way to know that the card is not present anymore. So,
theoretically, and ignoring the code layering for now, we can connect
that error to the card not present event and then ignore the error...

Hmmm.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.