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Date:   Sat, 23 Apr 2022 07:59:17 -0700
From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc:     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,
        ahalaney@redhat.com
Subject: Re: [PATCH v2 1/5] scsi: ufs: qcom: Fix acquiring the optional reset
 control line
Message-ID: <YmQURV7yQMof4RB8@ripper>
References: <20220423140245.394092-1-manivannan.sadhasivam@linaro.org>
 <20220423140245.394092-2-manivannan.sadhasivam@linaro.org>
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In-Reply-To: <20220423140245.394092-2-manivannan.sadhasivam@linaro.org>
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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

> +			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
>