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Message-ID: <d53f0b3e-a831-ed1e-9a8e-3c6902a81fdf@acm.org>
Date:   Fri, 9 Dec 2022 10:50:48 -0800
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Subject: Re: [PATCH v3 1/1] scsi: ufs: core: fix device management cmd timeout
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To:     Mason Zhang <mason.zhang@mediatek.com>,
        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>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Bean Huo <beanhuo@micron.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Jinyoung Choi <j-young.choi@samsung.com>
Cc:     linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org,
        Peter Wang <peter.wang@mediatek.com>,
        Peng Zhou <peng.zhou@mediatek.com>, wsd_upstream@mediatek.com
References: <20221209101321.30671-1-mason.zhang@mediatek.com>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <20221209101321.30671-1-mason.zhang@mediatek.com>
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On 12/9/22 02:13, Mason Zhang wrote:
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index b1f59a5fe632..6fe51b8d41f9 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -2979,35 +2979,31 @@ static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
>   		err = -ETIMEDOUT;
>   		dev_dbg(hba->dev, "%s: dev_cmd request timedout, tag %d\n",
>   			__func__, lrbp->task_tag);
> -		if (ufshcd_clear_cmds(hba, 1U << lrbp->task_tag) == 0) {
> +		if (ufshcd_clear_cmds(hba, 1U << lrbp->task_tag) == 0)
>   			/* successfully cleared the command, retry if needed */
>   			err = -EAGAIN;
> +		/*
> +		 * in case of an error, after clearing the doorbell,
> +		 * we also need to clear the task tag bit from the
> +		 * outstanding_reqs variable.
> +		 */
> +		spin_lock_irqsave(&hba->outstanding_lock, flags);
> +		pending = test_bit(lrbp->task_tag,
> +				   &hba->outstanding_reqs);
> +		if (pending) {
> +			hba->dev_cmd.complete = NULL;
> +			__clear_bit(lrbp->task_tag,
> +				    &hba->outstanding_reqs);
> +		}
> +		spin_unlock_irqrestore(&hba->outstanding_lock, flags);

This patch causes the 'task_tag' bit to be cleared from outstanding_reqs 
even if ufshcd_clear_cmds() failed. I think that's wrong.

Bart.