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Date:   Fri, 13 Nov 2020 13:28:13 +0800
From:   Can Guo <cang@codeaurora.org>
To:     Stanley Chu <stanley.chu@mediatek.com>
Cc:     linux-scsi@vger.kernel.org, martin.petersen@oracle.com,
        avri.altman@wdc.com, alim.akhtar@samsung.com, jejb@linux.ibm.com,
        beanhuo@micron.com, asutoshd@codeaurora.org,
        matthias.bgg@gmail.com, bvanassche@acm.org,
        linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kuohong.wang@mediatek.com, peter.wang@mediatek.com,
        chun-hung.wu@mediatek.com, andy.teng@mediatek.com,
        chaotian.jing@mediatek.com, cc.chou@mediatek.com,
        jiajie.hao@mediatek.com, alice.chao@mediatek.com
Subject: Re: [PATCH] scsi: ufs: Add retry flow for failed hba enabling
In-Reply-To: <20201112054537.22494-1-stanley.chu@mediatek.com>
References: <20201112054537.22494-1-stanley.chu@mediatek.com>
Message-ID: <473d79ef475169fac15f04c8da8f849e@codeaurora.org>
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On 2020-11-12 13:45, Stanley Chu wrote:
> Once hba enabling is failed, add retry mechanism and in the
> meanwhile allow vendors to apply specific handlings before
> the next retry. For example, vendors can do vendor-specific
> host reset flow in variant function "ufshcd_vops_hce_enable_notify()".
> 
> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>

Reviewed-by: Can Guo <cang@codeaurora.org>

> ---
>  drivers/scsi/ufs/ufshcd.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 8001bbfec5c0..9186ee01379a 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -4328,8 +4328,10 @@ static inline void ufshcd_hba_stop(struct 
> ufs_hba *hba)
>   */
>  static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
>  {
> -	int retry;
> +	int retry_outer = 3;
> +	int retry_inner;
> 
> +start:
>  	if (!ufshcd_is_hba_active(hba))
>  		/* change controller state to "reset state" */
>  		ufshcd_hba_stop(hba);
> @@ -4355,13 +4357,17 @@ static int ufshcd_hba_execute_hce(struct 
> ufs_hba *hba)
>  	ufshcd_delay_us(hba->vps->hba_enable_delay_us, 100);
> 
>  	/* wait for the host controller to complete initialization */
> -	retry = 50;
> +	retry_inner = 50;
>  	while (ufshcd_is_hba_active(hba)) {
> -		if (retry) {
> -			retry--;
> +		if (retry_inner) {
> +			retry_inner--;
>  		} else {
>  			dev_err(hba->dev,
>  				"Controller enable failed\n");
> +			if (retry_outer) {
> +				retry_outer--;
> +				goto start;
> +			}
>  			return -EIO;
>  		}
>  		usleep_range(1000, 1100);