Re: [PATCH v6 04/16] ufs: core: Defer adding host to scsi if mcq is supported

[Manivannan Sadhasivam]

On Mon, Nov 28, 2022 at 05:20:45PM -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.
> 
> Co-developed-by: Can Guo <quic_cang@xxxxxxxxxxx>
> Signed-off-by: Can Guo <quic_cang@xxxxxxxxxxx>
> Signed-off-by: Asutosh Das <quic_asutoshd@xxxxxxxxxxx>

Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>

Thanks,
Mani

> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
>  drivers/ufs/core/ufshcd.c | 24 ++++++++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index eca15b0..3c2220c 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -92,6 +92,11 @@
>  /* UFSHC 4.0 compliant HC support this mode, refer param_set_mcq_mode() */
>  static bool use_mcq_mode = true;
>  
> +static bool is_mcq_supported(struct ufs_hba *hba)
> +{
> +        return hba->mcq_sup && use_mcq_mode;
> +}
> +
>  static int param_set_mcq_mode(const char *val, const struct kernel_param *kp)
>  {
>  	int ret;
> @@ -8227,6 +8232,7 @@ 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;
>  
> @@ -8261,6 +8267,14 @@ 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);
> @@ -9857,10 +9871,12 @@ 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
>