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Date:   Mon, 16 Mar 2020 14:34:41 +0800
From:   Can Guo <cang@codeaurora.org>
To:     Stanley Chu <stanley.chu@mediatek.com>
Cc:     linux-scsi@vger.kernel.org, martin.peter~sen@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
Subject: Re: [PATCH v5 7/8] scsi: ufs: make HCE polling more compact to
 improve initialization latency
In-Reply-To: <20200316034218.11914-8-stanley.chu@mediatek.com>
References: <20200316034218.11914-1-stanley.chu@mediatek.com>
 <20200316034218.11914-8-stanley.chu@mediatek.com>
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On 2020-03-16 11:42, Stanley Chu wrote:
> Reduce the waiting period between each HCE (Host Controller Enable)
> polling from 5 ms to 1 ms. In the same time, increase the maximum 
> polling
> times to make "total polling time" unchanged approximately.
> 
> This change could make HCE initializatoin faster to improve latency of
> ufshcd initialization, error recovery, and resume behaviors.
> 
> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
> Reviewed-by: Avri Altman <avri.altman@wdc.com>

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

> ---
>  drivers/scsi/ufs/ufshcd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index dcbf45d547d8..cd33d07c56cf 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -4301,7 +4301,7 @@ int ufshcd_hba_enable(struct ufs_hba *hba)
>  	ufshcd_wait_us(hba->hba_enable_delay_us, 100, true);
> 
>  	/* wait for the host controller to complete initialization */
> -	retry = 10;
> +	retry = 50;
>  	while (ufshcd_is_hba_active(hba)) {
>  		if (retry) {
>  			retry--;
> @@ -4310,7 +4310,7 @@ int ufshcd_hba_enable(struct ufs_hba *hba)
>  				"Controller enable failed\n");
>  			return -EIO;
>  		}
> -		ufshcd_wait_us(5000, 100, true);
> +		ufshcd_wait_us(1000, 100, true);
>  	}
> 
>  	/* enable UIC related interrupts */