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Date:   Mon, 26 Sep 2022 16:17:24 -0500
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Grzegorz Halat <ghalat@redhat.com>
Cc:     stefan.buehler@tik.uni-stuttgart.de, sean.v.kelley@linux.intel.com,
        bhelgaas@google.com, bp@alien8.de, corbet@lwn.net,
        gregkh@linuxfoundation.org, kar.hin.ong@ni.com,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org, mingo@redhat.com, sassmann@kpanic.de,
        tglx@linutronix.de, x86@kernel.org
Subject: Re: boot interrupt quirk (also in 4.19.y) breaks serial ports (was:
 [PATCH v2 0/2] pci: Add boot interrupt quirk mechanism for Xeon chipsets)
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On Fri, Sep 23, 2022 at 09:20:30PM +0200, Grzegorz Halat wrote:
> On Wed, Sep 16 2020 at 12:12, Stefan B?hler wrote:
> > this quirk breaks our serial ports PCIe card (i.e. we don't see any
> > output from the connected devices; no idea whether anything we send
> > reaches them):
> 
> I have the same problem, also with a PCI serial adapter from Oxford
> Semiconductor.  I've bisected the kernel and it was introduced in
> b88bf6c3b6ff.  When the system is booted with "pci=noioapicquirk"
> then the PCI card works fine.  The CPU is Intel Xeon E5-2680 v3 @
> 2.50GHz.
> 
> Sean, do you have any news about this issue?

I think Sean has moved on and isn't available to work this issue.

To help whoever *can* work on it, would you mind attaching the
complete dmesg log and "sudo lspci -vv" output for your system?  Then
we can potentially tweak the quirk to not break your system.

Bjorn