Re: [PATCH v1 3/5] scsi: ufs: customize flush threshold for WriteBooster

From: "Asutosh Das (asd)" <asutoshd@codeaurora.org>
To: Stanley Chu <stanley.chu@mediatek.com>,
	linux-scsi@vger.kernel.org, martin.petersen@oracle.com,
	avri.altman@wdc.com, alim.akhtar@samsung.com, jejb@linux.ibm.com
Cc: bvanassche@acm.org, andy.teng@mediatek.com,
	chun-hung.wu@mediatek.com, kuohong.wang@mediatek.com,
	linux-kernel@vger.kernel.org, cang@codeaurora.org,
	linux-mediatek@lists.infradead.org, peter.wang@mediatek.com,
	matthias.bgg@gmail.com, linux-arm-kernel@lists.infradead.org,
	beanhuo@micron.com
Subject: Re: [PATCH v1 3/5] scsi: ufs: customize flush threshold for WriteBooster
Date: Fri, 8 May 2020 11:12:23 -0700	[thread overview]
Message-ID: <4196ff98-093e-3708-d166-a7a7c6046c57@codeaurora.org> (raw)
In-Reply-To: <20200508171513.14665-4-stanley.chu@mediatek.com>

On 5/8/2020 10:15 AM, Stanley Chu wrote:
> Allow flush threshold for WriteBooster to be customizable by
> vendors. To achieve this, make the value as a variable in struct
> ufs_hba first.
> 
> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
> ---
>   drivers/scsi/ufs/ufshcd.c | 6 ++++--
>   drivers/scsi/ufs/ufshcd.h | 1 +
>   2 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index cdacbe6378a1..9a0ce6550c2f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -5301,8 +5301,8 @@ static bool ufshcd_wb_presrv_usrspc_keep_vcc_on(struct ufs_hba *hba,
>   			 cur_buf);
>   		return false;
>   	}
> -	/* Let it continue to flush when >60% full */
> -	if (avail_buf < UFS_WB_40_PERCENT_BUF_REMAIN)
> +	/* Let it continue to flush when available buffer exceeds threshold */
> +	if (avail_buf < hba->vps->wb_flush_threshold)
>   		return true;
>   
>   	return false;
> @@ -6839,6 +6839,7 @@ static void ufshcd_wb_probe(struct ufs_hba *hba, u8 *desc_buf)
>   		if (!d_lu_wb_buf_alloc)
>   			goto wb_disabled;
>   	}
> +
Is this newline needed?

>   	return;
>   
>   wb_disabled:
> @@ -7462,6 +7463,7 @@ static const struct attribute_group *ufshcd_driver_groups[] = {
>   
>   static struct ufs_hba_variant_params ufs_hba_vps = {
>   	.hba_enable_delay_us		= 1000,
> +	.wb_flush_threshold		= UFS_WB_40_PERCENT_BUF_REMAIN,
>   	.devfreq_profile.polling_ms	= 100,
>   	.devfreq_profile.target		= ufshcd_devfreq_target,
>   	.devfreq_profile.get_dev_status	= ufshcd_devfreq_get_dev_status,
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index f7bdf52ba8b0..e3dfb48e669e 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -570,6 +570,7 @@ struct ufs_hba_variant_params {
>   	struct devfreq_dev_profile devfreq_profile;
>   	struct devfreq_simple_ondemand_data ondemand_data;
>   	u16 hba_enable_delay_us;
> +	u32 wb_flush_threshold;
>   };
>   
>   /**
> 

Patch[3] & [4] may be combined into a single patch perhaps?
Patch[4] just redoes what [3] did in a different way, so might as well 
just do what patch[4] does right away.

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
Linux Foundation Collaborative Project

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