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Subject: Re: [PATCH v8 2/4] scsi: ufs: Introduce HPB feature
Reply-To: daejun7.park@samsung.com
From:   Daejun Park <daejun7.park@samsung.com>
To:     Bart Van Assche <bvanassche@acm.org>,
        Daejun Park <daejun7.park@samsung.com>,
        "avri.altman@wdc.com" <avri.altman@wdc.com>,
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        "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>,
        "tomas.winkler@intel.com" <tomas.winkler@intel.com>,
        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>,
        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>
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Date:   Thu, 13 Aug 2020 11:13:09 +0900
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Hi Bart,

On 2020-08-06 02:11, Daejun Park wrote:
> > +static void ufshpb_issue_hpb_reset_query(struct ufs_hba *hba)
> > +{
> > +    int err;
> > +    int retries;
> > +
> > +    for (retries = 0; retries < HPB_RESET_REQ_RETRIES; retries++) {
> > +        err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_SET_FLAG,
> > +                QUERY_FLAG_IDN_HPB_RESET, 0, NULL);
> > +        if (err)
> > +            dev_dbg(hba->dev,
> > +                "%s: failed with error %d, retries %d\n",
> > +                __func__, err, retries);
> > +        else
> > +            break;
> > +    }
> > +
> > +    if (err) {
> > +        dev_err(hba->dev,
> > +            "%s setting fHpbReset flag failed with error %d\n",
> > +            __func__, err);
> > +        return;
> > +    }
> > +}
> 
> Please change the "break" into an early return, remove the last
> occurrence "if (err)" and remove the final return statement.

OK, I will.

> 
> > +static void ufshpb_check_hpb_reset_query(struct ufs_hba *hba)
> > +{
> > +    int err;
> > +    bool flag_res = true;
> > +    int try = 0;
> > +
> > +    /* wait for the device to complete HPB reset query */
> > +    do {
> > +        if (++try == HPB_RESET_REQ_RETRIES)
> > +            break;
> > +
> > +        dev_info(hba->dev,
> > +            "%s start flag reset polling %d times\n",
> > +            __func__, try);
> > +
> > +        /* Poll fHpbReset flag to be cleared */
> > +        err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG,
> > +                QUERY_FLAG_IDN_HPB_RESET, 0, &flag_res);
> > +        usleep_range(1000, 1100);
> > +    } while (flag_res);
> > +
> > +    if (err) {
> > +        dev_err(hba->dev,
> > +            "%s reading fHpbReset flag failed with error %d\n",
> > +            __func__, err);
> > +        return;
> > +    }
> > +
> > +    if (flag_res) {
> > +        dev_err(hba->dev,
> > +            "%s fHpbReset was not cleared by the device\n",
> > +            __func__);
> > +    }
> > +}
> 
> Should "polling %d times" perhaps be changed into "attempt %d"?

I will change it.

> The "if (err)" statement may be reached without "err" having been
> initialized. Please fix.

OK, I will initialize err to 0.

> Additionally, please change the do-while loop into a for-loop, e.g. as
> follows:
> 
>     for (try = 0; try < HPB_RESET_REQ_RETRIES; try++)
>         ...

OK, I will change do-while to for-loop.

Thanks,

Daejun