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Date:   Tue, 26 Oct 2021 11:53:48 -0500
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc:     Bjorn Helgaas <bhelgaas@google.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Anthony Wong <anthony.wong@canonical.com>,
        Linux PCI <linux-pci@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        Vidya Sagar <vidyas@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>
Subject: Re: [PATCH v2 3/3] PCI/ASPM: Add LTR sysfs attributes
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On Tue, Oct 26, 2021 at 10:28:38AM +0800, Kai-Heng Feng wrote:

> What if we fallback to the original approach and use the VMD driver
> to enable ASPM and LTR values?  At least I think Intel should be
> able to provide correct values for their SoC.

Can you post the patches for that?  I'm not sure exactly what the
original approach was.  Are these the same as the downstream support
you mention below?

> So what other options do we have if we want to enable VMD ASPM while
> keeping CONFIG_PCIEASPM_DEFAULT=y?  Right now we enabled the VMD
> ASPM/LTR bits in downstream kernel, but other distro users may want
> to have upstream support for this.