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Date:   Tue, 29 Nov 2022 09:43:10 +0100
From:   "hch@lst.de" <hch@lst.de>
To:     "Rao, Lei" <lei.rao@intel.com>
Cc:     Chaitanya Kulkarni <chaitanyak@nvidia.com>,
        "kbusch@kernel.org" <kbusch@kernel.org>,
        "axboe@fb.com" <axboe@fb.com>, "hch@lst.de" <hch@lst.de>,
        "sagi@grimberg.me" <sagi@grimberg.me>,
        "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] nvme: clear the prp2 field of the nvme command.
Message-ID: <20221129084310.GB25609@lst.de>
References: <20221129014711.91305-1-lei.rao@intel.com> <15de4902-03e7-0d2c-4b4c-45d713d0f1fd@nvidia.com> <4cee0097-4f08-1990-112f-6e39229f59ef@intel.com>
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On Tue, Nov 29, 2022 at 12:50:57PM +0800, Rao, Lei wrote:
> stricter checks, and if prp2 is not used but has a value, some warnings will be
> printed. According to the NVMe spec, it seems to write a reserved field produces
> an undefined result, so maybe clearing it is better.

NVMe is a little weird about reserved fields settable by the host.
I don't think your controllers warnings are correct, but given that
the cost of clearing is very low I think we should clear it in Linux.
Please resend a patch with the clearing in the right place as suggested
in my previous mail.