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Message-ID: <7ba3bbb8-a5c3-4ecd-9c2a-c9586c9d6bf2@acm.org>
Date: Fri, 7 Jun 2024 06:33:03 -0600
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Subject: Re: [PATCH] scsi: ufs: core: quiesce request queues before check
 pending cmds
To: Ziqi Chen <quic_ziqichen@quicinc.com>, quic_cang@quicinc.com,
 mani@kernel.org, beanhuo@micron.com, avri.altman@wdc.com,
 junwoo80.lee@samsung.com, martin.petersen@oracle.com,
 quic_nguyenb@quicinc.com, quic_nitirawa@quicinc.com,
 quic_rampraka@quicinc.com
Cc: linux-scsi@vger.kernel.org, Alim Akhtar <alim.akhtar@samsung.com>,
 "James E.J. Bottomley" <jejb@linux.ibm.com>,
 Peter Wang <peter.wang@mediatek.com>,
 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
 Maramaina Naresh <quic_mnaresh@quicinc.com>,
 Asutosh Das <quic_asutoshd@quicinc.com>,
 open list <linux-kernel@vger.kernel.org>
References: <1717754818-39863-1-git-send-email-quic_ziqichen@quicinc.com>
Content-Language: en-US
From: Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <1717754818-39863-1-git-send-email-quic_ziqichen@quicinc.com>
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On 6/7/24 04:06, Ziqi Chen wrote:
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 21429ee..1afa862 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -1392,7 +1392,7 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba, u64 timeout_us)
>   	 * make sure that there are no outstanding requests when
>   	 * clock scaling is in progress
>   	 */
> -	ufshcd_scsi_block_requests(hba);
> +	blk_mq_quiesce_tagset(&hba->host->tag_set);
>   	mutex_lock(&hba->wb_mutex);
>   	down_write(&hba->clk_scaling_lock);
>   
> @@ -1401,7 +1401,7 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba, u64 timeout_us)
>   		ret = -EBUSY;
>   		up_write(&hba->clk_scaling_lock);
>   		mutex_unlock(&hba->wb_mutex);
> -		ufshcd_scsi_unblock_requests(hba);
> +		blk_mq_unquiesce_tagset(&hba->host->tag_set);
>   		goto out;
>   	}
>   
> @@ -1422,7 +1422,7 @@ static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, int err, bool sc
>   
>   	mutex_unlock(&hba->wb_mutex);
>   
> -	ufshcd_scsi_unblock_requests(hba);
> +	blk_mq_unquiesce_tagset(&hba->host->tag_set);
>   	ufshcd_release(hba);
>   }

Why to replace only those ufshcd_scsi_block_requests() /
ufshcd_scsi_unblock_requests() calls? I don't think that it is ever safe to
use these functions instead of  blk_mq_quiesce_tagset() /
blk_mq_unquiesce_tagset(). Please replace all ufshcd_scsi_block_requests() /
ufshcd_scsi_unblock_requests() calls and remove the
ufshcd_scsi_*block_requests() functions.

Thanks,

Bart.