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Subject: Re: [PATCH v19 2/3] scsi: ufs: L2P map management for HPB read
From:   Bean Huo <huobean@gmail.com>
To:     Avri Altman <Avri.Altman@wdc.com>,
        "daejun7.park@samsung.com" <daejun7.park@samsung.com>,
        Greg KH <gregkh@linuxfoundation.org>,
        "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
        "asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
        "stanley.chu@mediatek.com" <stanley.chu@mediatek.com>,
        "cang@codeaurora.org" <cang@codeaurora.org>,
        "bvanassche@acm.org" <bvanassche@acm.org>,
        ALIM AKHTAR <alim.akhtar@samsung.com>
Cc:     "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Sung-Jun Park <sungjun07.park@samsung.com>,
        yongmyung lee <ymhungry.lee@samsung.com>,
        Jinyoung CHOI <j-young.choi@samsung.com>,
        BoRam Shin <boram.shin@samsung.com>,
        SEUNGUK SHIN <seunguk.shin@samsung.com>
Date:   Fri, 05 Feb 2021 12:54:14 +0100
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On Fri, 2021-02-05 at 11:42 +0000, Avri Altman wrote:
> > "If the requested field of the HPB Region or HPB Sub-Region is out
> > of
> > range, then the device shall terminate the command by sending
> > RESPONSE
> > UPIU with CHECK CONDITION status, with the SENSE KEY set to ILLEGAL
> > REQUEST, and the additional sense code set to INVALID FIELD IN CDB"
> 
> You don't need to worry about setting invalid ppn to HPB-READ command
> - 
> you'll never get a read request for those LBAs.
> 
> Say all subregions are 16MB and the last subregion of the last region
> is 10MB.
> Keep all sizes the same - 16MB, and the ppn of the last subregion
> contain some invalid data.
> But you'll never get a read request for those LBAs anyway - they
> don't exist,
> so you'll never get to use those invalid ppns.
> 
> Thanks,
> Avri

Hi Avri
ah, I don't know if your above comments are inline with Spec.

Spec:
"A HPB Region is divided into HPB Sub-Regions. HPB Sub-Region size is
specified by the bHPBSubRegionSize parameter of Geometry Descriptor.
HPB Sub-Regions are equally sized except for the last one which is
smaller if the last HPB Region is not an interger multiple of
bHPBSubRegionSize."

It is not invalidate ppn concern, it is illegal request issue in sense
key.

Kind regards,
Bean