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Date:   Thu, 18 Apr 2019 07:48:21 -0600
From:   Keith Busch <kbusch@kernel.org>
To:     Aaron Ma <aaron.ma@canonical.com>
Cc:     Maxim Levitsky <mlevitsk@redhat.com>, linux-kernel@vger.kernel.org,
        linux-nvme@lists.infradead.org, keith.busch@intel.com, axboe@fb.com
Subject: Re: [PATCH] nvme: determine the number of IO queues
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On Thu, Apr 18, 2019 at 02:21:57PM +0800, Aaron Ma wrote:
> On 4/18/19 1:33 AM, Maxim Levitsky wrote:
> >>
> >> Maybe its better to add a quirk for the broken device, which needs this?
> 
> Adding quirk only makes the code more complicated.
> This patch doesn't change the default behavior.
> Only handle the NVME error code.

It does change the default behavior. If I have a degraded controller that
can't do IO in a machine with 1000's of CPUs, I have to iterate this
non-standard behavior 1000's of times before the drive is servicable
again. We currenlty figure that out in just a single try.

At least the quirks document *why* the driver is doing non-standard
behavior. We do the IO queue quirks for Macbooks, for example.

But why don't you file a bug report with the device vendor instead? Surely
a firmware fix provides the best possible outcome, and would make this
device work not only in all versions of Linux, but also every standard
compliant driver for any OS.