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Date:   Mon, 25 Apr 2022 07:59:31 -0500
From:   Andrew Halaney <ahalaney@redhat.com>
To:     Bjorn Andersson <bjorn.andersson@linaro.org>
Cc:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        martin.petersen@oracle.com, jejb@linux.ibm.com,
        avri.altman@wdc.com, alim.akhtar@samsung.com,
        linux-arm-msm@vger.kernel.org, quic_asutoshd@quicinc.com,
        quic_cang@quicinc.com, linux-scsi@vger.kernel.org,
        linux-kernel@vger.kernel.org, bvanassche@acm.org
Subject: Re: [PATCH v2 1/5] scsi: ufs: qcom: Fix acquiring the optional reset
 control line
Message-ID: <20220425125931.g3ub2fprsfa56bl6@halaneylaptop>
References: <20220423140245.394092-1-manivannan.sadhasivam@linaro.org>
 <20220423140245.394092-2-manivannan.sadhasivam@linaro.org>
 <YmQURV7yQMof4RB8@ripper>
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On Sat, Apr 23, 2022 at 07:59:17AM -0700, Bjorn Andersson wrote:
> On Sat 23 Apr 07:02 PDT 2022, Manivannan Sadhasivam wrote:
> 
> > On Qcom UFS platforms, the reset control line seems to be optional
> > (for SoCs like MSM8996 and probably for others too). The current logic
> > tries to mimic the `devm_reset_control_get_optional()` API but it also
> > continues the probe if there is an error with the declared reset line in
> > DT/ACPI.
> > 
> > In an ideal case, if the reset line is not declared in DT/ACPI, the probe
> > should continue. But if there is problem in acquiring the declared reset
> > line (like EPROBE_DEFER) it should fail and return the appropriate error
> > code.
> > 
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >  drivers/scsi/ufs/ufs-qcom.c | 10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> > index 0d2e950d0865..bee81b45299e 100644
> > --- a/drivers/scsi/ufs/ufs-qcom.c
> > +++ b/drivers/scsi/ufs/ufs-qcom.c
> > @@ -1002,13 +1002,13 @@ static int ufs_qcom_init(struct ufs_hba *hba)
> >  	host->hba = hba;
> >  	ufshcd_set_variant(hba, host);
> >  
> > -	/* Setup the reset control of HCI */
> > -	host->core_reset = devm_reset_control_get(hba->dev, "rst");
> > +	/* Setup the optional reset control of HCI */
> > +	host->core_reset = devm_reset_control_get_optional(hba->dev, "rst");
> >  	if (IS_ERR(host->core_reset)) {
> >  		err = PTR_ERR(host->core_reset);
> > -		dev_warn(dev, "Failed to get reset control %d\n", err);
> > -		host->core_reset = NULL;
> > -		err = 0;
> > +		if (err != -EPROBE_DEFER)
> 
> dev_err_probe() does this comparison internally, so you can omit it
> here.
> 
> With that removed, feel free to add my:
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> 
> Regards,
> Bjorn

+1; well with that change in place:
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>

Thanks,
Andrew

> 
> > +			dev_err_probe(dev, err, "Failed to get reset control\n");
> > +		goto out_variant_clear;
> >  	}
> >  
> >  	/* Fire up the reset controller. Failure here is non-fatal. */
> > -- 
> > 2.25.1
> > 
>