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Date:   Tue, 01 Dec 2020 10:18:21 +0200
From:   =?UTF-8?Q?Lauren=C8=9Biu_Nicola?= <lnicola@dend.ro>
To:     "Thomas Gleixner" <tglx@linutronix.de>
Cc:     mingo@kernel.org, bp@alien8.de, x86@kernel.org, trivial@kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        "Tom Lendacky" <thomas.lendacky@amd.com>
Subject: Re: [PATCH] x86/irq: Lower unhandled irq error severity
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On Tue, Dec 1, 2020, at 01:34, Thomas Gleixner wrote:
> The point is that for some cases this can result in a non working
> machine which just hangs and if it's below the usual loglevel cutoff,
> then it's not visible, which is more annoying than a non-quiet boot if=

> you're affected.

For most (desktop) users "errors" will be shown by default, and if anyon=
e is having trouble, they can temporarily remove "quiet" from the kernel=
 command line while debugging it, so it's easy. On the other hand, I don=
't think it's possible to silence the emergency messages (and I'd still =
like to see them for any "something is on fire").

The only other use of `pr_emerg_ratelimited` seems to be an informationa=
l message shown on non-AMD MCEs ("run mcelog --ascii"). `pr_emerg` is us=
ed in more places, but they do sound like critical situations that will =
bring the system down anyway.

>=20
> We are looking into a way to mitigate that AMD wreckage, but so far we=

> don't even know where exactly this comes from. The reason why we are
> pretty sure that it is a BIOS/Firmware issue is that some people
> reported it to be gone after a BIOS update and quite some machines do
> not have this issue at all.

In my case, it's latest BIOS version available. Could be AGESA-related, =
maybe we could install a no-op handler for that IRQ?

>=20
> Just for completeness sake. Can you provide the line in /proc/interrup=
ts
> for irq 7 on that machine?


  55:          0          0          0          0          0          0 =
         0          0          0          0          0          0       =
   0          0          0          0          0          0          0  =
        0          0          0          0          0          0        =
  0          0          0          0          0          0          0  I=
R-PCI-MSI 2625543-edge      xhci_hcd

PS: I now see that this was reported a lot of times, including e.g. http=
s://lkml.org/lkml/2019/3/6/97.

Thanks,
Lauren=C8=9Biu