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Date:   Mon, 28 Nov 2022 20:12:22 +0530
From:   Manivannan Sadhasivam <mani@kernel.org>
To:     Asutosh Das <quic_asutoshd@quicinc.com>
Cc:     quic_cang@quicinc.com, martin.petersen@oracle.com,
        linux-scsi@vger.kernel.org, quic_nguyenb@quicinc.com,
        quic_xiaosenh@quicinc.com, stanley.chu@mediatek.com,
        eddie.huang@mediatek.com, daejun7.park@samsung.com,
        bvanassche@acm.org, avri.altman@wdc.com, beanhuo@micron.com,
        linux-arm-msm@vger.kernel.org,
        Alim Akhtar <alim.akhtar@samsung.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        Jinyoung Choi <j-young.choi@samsung.com>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 04/16] ufs: core: Defer adding host to scsi if mcq is
 supported
Message-ID: <20221128144222.GD62721@thinkpad>
References: <cover.1669176158.git.quic_asutoshd@quicinc.com>
 <b75e35e1c23b428a6c55396c0fcda5ea22b4e33e.1669176158.git.quic_asutoshd@quicinc.com>
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Precedence: bulk

On Tue, Nov 22, 2022 at 08:10:17PM -0800, Asutosh Das wrote:
> If MCQ support is present, enabling it after MCQ support
> has been configured would require reallocating tags and memory.
> It would also free up the already allocated memory in
> Single Doorbell Mode. So defer invoking scsi_add_host() until
> MCQ is configured.

Why cannot we do it for non MCQ case as well?

Thanks,
Mani

> 
> Co-developed-by: Can Guo <quic_cang@quicinc.com>
> Signed-off-by: Can Guo <quic_cang@quicinc.com>
> Signed-off-by: Asutosh Das <quic_asutoshd@quicinc.com>
> ---
>  drivers/ufs/core/ufshcd.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 08be8ad..42c49ce 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -8208,6 +8208,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool init_dev_params)
>  	int ret;
>  	unsigned long flags;
>  	ktime_t start = ktime_get();
> +	struct Scsi_Host *host = hba->host;
>  
>  	hba->ufshcd_state = UFSHCD_STATE_RESET;
>  
> @@ -8242,6 +8243,14 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool init_dev_params)
>  		ret = ufshcd_device_params_init(hba);
>  		if (ret)
>  			goto out;
> +
> +		if (is_mcq_supported(hba)) {
> +			ret = scsi_add_host(host, hba->dev);
> +			if (ret) {
> +				dev_err(hba->dev, "scsi_add_host failed\n");
> +				goto out;
> +			}
> +		}
>  	}
>  
>  	ufshcd_tune_unipro_params(hba);
> @@ -9838,10 +9847,12 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
>  		hba->is_irq_enabled = true;
>  	}
>  
> -	err = scsi_add_host(host, hba->dev);
> -	if (err) {
> -		dev_err(hba->dev, "scsi_add_host failed\n");
> -		goto out_disable;
> +	if (!is_mcq_supported(hba)) {
> +		err = scsi_add_host(host, hba->dev);
> +		if (err) {
> +			dev_err(hba->dev, "scsi_add_host failed\n");
> +			goto out_disable;
> +		}
>  	}
>  
>  	hba->tmf_tag_set = (struct blk_mq_tag_set) {
> -- 
> 2.7.4
> 

-- 
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