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Date:   Wed, 03 Mar 2021 18:05:07 +0800
From:   Can Guo <cang@codeaurora.org>
To:     Adrian Hunter <adrian.hunter@intel.com>
Cc:     "Martin K . Petersen" <martin.petersen@oracle.com>,
        "James E . J . Bottomley" <jejb@linux.ibm.com>,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        Bean Huo <huobean@gmail.com>,
        Asutosh Das <asutoshd@codeaurora.org>,
        Stanley Chu <stanley.chu@mediatek.com>
Subject: Re: [PATCH] scsi: ufs: Fix incorrect ufshcd_state after
 ufshcd_reset_and_restore()
In-Reply-To: <20210301191940.15247-1-adrian.hunter@intel.com>
References: <20210301191940.15247-1-adrian.hunter@intel.com>
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On 2021-03-02 03:19, Adrian Hunter wrote:
> If ufshcd_probe_hba() fails it sets ufshcd_state to UFSHCD_STATE_ERROR,
> however, if it is called again, as it is within a loop in
> ufshcd_reset_and_restore(), and succeeds, then it will not set the 
> state
> back to UFSHCD_STATE_OPERATIONAL unless the state was
> UFSHCD_STATE_RESET.
> 
> That can result in the state being UFSHCD_STATE_ERROR even though
> ufshcd_reset_and_restore() is successful and returns zero.
> 
> Fix by initializing the state to UFSHCD_STATE_RESET in the start of 
> each
> loop in ufshcd_reset_and_restore().  If there is an error,
> ufshcd_reset_and_restore() will change the state to UFSHCD_STATE_ERROR,
> otherwise ufshcd_probe_hba() will have set the state appropriately.
> 
> Fixes: 4db7a2360597 ("scsi: ufs: Fix concurrency of error handler and
> other error recovery paths")
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
>  drivers/scsi/ufs/ufshcd.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 77161750c9fb..91a403afe038 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -7031,6 +7031,8 @@ static int ufshcd_reset_and_restore(struct 
> ufs_hba *hba)
>  	spin_unlock_irqrestore(hba->host->host_lock, flags);
> 
>  	do {
> +		hba->ufshcd_state = UFSHCD_STATE_RESET;
> +
>  		/* Reset the attached device */
>  		ufshcd_device_reset(hba);

Hi Adrian,

I've proposed a fix to get it addressed - 
https://lore.kernel.org/patchwork/patch/1383817/

Thanks,

Can Guo.