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Message-ID: <c19782e36c9b4a8319f2f16102e1823dc6a33d3c.camel@linux.intel.com>
Subject: Re: [PATCH] PCI/ASPM: Enable ASPM for links under VMD domain
From:   David Fugate <david.fugate@linux.intel.com>
Reply-To: david.fugate@linux.intel.com
To:     Christoph Hellwig <hch@infradead.org>,
        Kai Heng Feng <kai.heng.feng@canonical.com>
Cc:     Bjorn Helgaas <bhelgaas@google.com>, jonathan.derrick@intel.com,
        Mario.Limonciello@dell.com, Heiner Kallweit <hkallweit1@gmail.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Xiongfeng Wang <wangxiongfeng2@huawei.com>,
        Krzysztof Wilczynski <kw@linux.com>,
        "open list:PCI SUBSYSTEM" <linux-pci@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        "Huffman, Amber" <amber.huffman@intel.com>, david.fugate@intel.com
Date:   Wed, 02 Sep 2020 13:48:19 -0600
In-Reply-To: <20200825065634.GA2691@infradead.org>
References: <20200821123222.32093-1-kai.heng.feng@canonical.com>
         <20200825062320.GA27116@infradead.org>
         <08080FC7-861B-472A-BD7D-02D33926677F@canonical.com>
         <20200825065634.GA2691@infradead.org>
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On Tue, 2020-08-25 at 07:56 +0100, Christoph Hellwig wrote:
> while adding absolutely no value.  Basically we have to add a large
> chunk of kernel code just to undo silicone/firmware Intel added to
> their
> platform to make things complicated.  I mean it is their platform and
> if
> they want a "make things complicated" option that is fine, but it
> should
> not be on by default.


Thanks for your feedback.

Over the years, I've been forwarded numerous emails from VMD customers 
praising it's ability to prevent Linux kernel panics upon hot-removals
and inserts of U.2 NVMe drives. Many were migrating from SATA drives,
which didn't have this issue, and considered it a showstopper to NVMe
adoption. I hope we can all agree reliable and robust hot-plug support
adds value.