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Subject: Re: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer
From:   Bean Huo <huobean@gmail.com>
To:     Alim Akhtar <alim.akhtar@gmail.com>,
        Avri Altman <Avri.Altman@wdc.com>
Cc:     "daejun7.park@samsung.com" <daejun7.park@samsung.com>,
        ALIM AKHTAR <alim.akhtar@samsung.com>,
        "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
        "asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
        "beanhuo@micron.com" <beanhuo@micron.com>,
        "stanley.chu@mediatek.com" <stanley.chu@mediatek.com>,
        "cang@codeaurora.org" <cang@codeaurora.org>,
        "bvanassche@acm.org" <bvanassche@acm.org>,
        "tomas.winkler@intel.com" <tomas.winkler@intel.com>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Sang-yoon Oh <sangyoon.oh@samsung.com>,
        Sung-Jun Park <sungjun07.park@samsung.com>,
        yongmyung lee <ymhungry.lee@samsung.com>,
        Jinyoung CHOI <j-young.choi@samsung.com>,
        Adel Choi <adel.choi@samsung.com>,
        BoRam Shin <boram.shin@samsung.com>
Date:   Wed, 17 Jun 2020 11:41:55 +0200
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On Wed, 2020-06-17 at 14:27 +0530, Alim Akhtar wrote:
> > > > > +       init_waitqueue_head(&hba->ufsf.sdev_wait);
> > > > > +       atomic_set(&hba->ufsf.slave_conf_cnt, 0);
> > > > > +
> > > > > +       if (hba->dev_info.wspecversion >=
> > > > > HPB_SUPPORTED_VERSION &&
> > > > > +           (hba->dev_info.b_ufs_feature_sup &
> > > > > UFS_DEV_HPB_SUPPORT))
> > > > 
> > > > How about removing this check "(hba->dev_info.wspecversion >=
> > > > HPB_SUPPORTED_VERSION" since ufs with lower version than v3.1
> > > > can add
> > > > HPB feature by FFU,
> > > > if (hba->dev_info.b_ufs_feature_sup 
> > > > &UFS_FEATURE_SUPPORT_HPB_BIT) is
> > > > enough.
> > > 
> > > OK, changing it seems no problem. But I want to know what other
> > > people
> > > think
> > > about this version checking code.
> > 
> > HPB1.0 isn't part of ufs3.1, but published only later.
> > Allowing earlier versions will required to quirk the descriptor
> > sizes.
> > I see Bean's point here, but I vote for adding it in a single
> > quirk, when the time comes.
> > 
> 
> I second Avri here, older devices need a quirk to handle, let do that
> as a separate patch.
> > Thanks,
> > Avri
> 
> 

what is useful point of adding a quirk for this?

From the customer side piont, they just get our FW image, and then do
FFU. If adding a quirk here, that means they also need to change UFS
driver. Also,  you expand the qurik structure.


from cambridge dictionary: 
Qurik: 
	an unusual habit or part of someone's personality, or something
	that
is strange and unexpected.

HPB feature is unexpected??


please tell me the useful point of adding a Quirk.

Bean
>