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Date:   Thu, 22 Jul 2021 16:48:43 -0500
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Alex Williamson <alex.williamson@redhat.com>,
        "Raj, Ashok" <ashok.raj@intel.com>,
        Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org,
        "David S. Miller" <davem@davemloft.net>,
        Kevin Tian <kevin.tian@intel.com>,
        Marc Zyngier <maz@kernel.org>, Ingo Molnar <mingo@kernel.org>,
        x86@kernel.org
Subject: Re: [patch 4/8] PCI/MSI: Enforce MSI[X] entry updates to be visible
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On Wed, Jul 21, 2021 at 09:11:30PM +0200, Thomas Gleixner wrote:
> Nothing enforces the posted writes to be visible when the function
> returns. Flush them even if the flush might be redundant when the entry is
> masked already as the unmask will flush as well. This is either setup or a
> rare affinity change event so the extra flush is not the end of the world.
> 
> While this is more a theoretical issue especially the X86 MSI affinity
> stter mechanism relies on the assumption that the update has reached the

stter?

> hardware when the function returns.
> 
> Again, as this never has been enfocred the Fixes tag refers to a commit in:

s/enfocred/enforced/

>    git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git