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Date:   Thu, 30 Jan 2020 17:26:06 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Bjorn Helgaas <helgaas@kernel.org>
Cc:     Alexandru Gagniuc <mr.nuke.me@gmail.com>,
        Alexandru Gagniuc <alex_gagniuc@dellteam.com>,
        Keith Busch <keith.busch@intel.com>, Jens Axboe <axboe@fb.com>,
        Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Jan Vesely <jano.vesely@gmail.com>,
        Lukas Wunner <lukas@wunner.de>,
        Alex Williamson <alex.williamson@redhat.com>,
        Austin Bolen <austin_bolen@dell.com>,
        Shyam Iyer <Shyam_Iyer@dell.com>,
        Sinan Kaya <okaya@kernel.org>, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: Issues with "PCI/LINK: Report degraded links via link
 bandwidth notification"
Message-ID: <20200130162606.GB6377@lst.de>
References: <20200115221008.GA191037@google.com> <20200120023326.GA149019@google.com>
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On Sun, Jan 19, 2020 at 08:33:26PM -0600, Bjorn Helgaas wrote:
> NVMe, GPU folks, do your drivers or devices change PCIe link
> speed/width for power saving or other reasons?  When CONFIG_PCIE_BW=y,
> the PCI core interprets changes like that as problems that need to be
> reported.

The NVMe driver doesn't.  For devices I don't know of any, but Ican't
find anything in the spec that would forbid it.