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Subject: Re: [PATCH v3 4/9] scsi: ufs: Complete the cmd before returning in
 queuecommand
To:     Can Guo <cang@codeaurora.org>, asutoshd@codeaurora.org,
        nguyenb@codeaurora.org, hongwus@codeaurora.org,
        ziqichen@codeaurora.org, linux-scsi@vger.kernel.org,
        kernel-team@android.com
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Bean Huo <beanhuo@micron.com>,
        Jaegeuk Kim <jaegeuk@kernel.org>,
        open list <linux-kernel@vger.kernel.org>
References: <1623300218-9454-1-git-send-email-cang@codeaurora.org>
 <1623300218-9454-5-git-send-email-cang@codeaurora.org>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <d017548a-16fb-8ad0-2363-09dad00c9642@acm.org>
Date:   Fri, 11 Jun 2021 13:52:18 -0700
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On 6/9/21 9:43 PM, Can Guo wrote:
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 0c9d2ee..7dc0fda 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -2758,6 +2758,16 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>  		goto out;
>  	}
>  
> +	if (unlikely(test_bit(tag, &hba->outstanding_reqs))) {
> +		if (hba->wl_pm_op_in_progress) {
> +			set_host_byte(cmd, DID_BAD_TARGET);
> +			cmd->scsi_done(cmd);
> +		} else {
> +			err = SCSI_MLQUEUE_HOST_BUSY;
> +		}
> +		goto out;
> +	}
> +
>  	hba->req_abort_count = 0;
>  
>  	err = ufshcd_hold(hba, true);
> @@ -2768,15 +2778,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>  	WARN_ON(ufshcd_is_clkgating_allowed(hba) &&
>  		(hba->clk_gating.state != CLKS_ON));
>  
> -	if (unlikely(test_bit(tag, &hba->outstanding_reqs))) {
> -		if (hba->wl_pm_op_in_progress)
> -			set_host_byte(cmd, DID_BAD_TARGET);
> -		else
> -			err = SCSI_MLQUEUE_HOST_BUSY;
> -		ufshcd_release(hba);
> -		goto out;
> -	}
> -
>  	lrbp = &hba->lrb[tag];
>  	WARN_ON(lrbp->cmd);
>  	lrbp->cmd = cmd;

Can the code under "if (unlikely(test_bit(tag,
&hba->outstanding_reqs)))" be deleted instead of moving it? I don't
think that it is useful to verify whether the block layer tag allocator
works correctly. Additionally, I'm not aware of any similar code in any
other SCSI LLD.

Thanks,

Bart.