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Date:   Thu, 24 Dec 2020 10:21:09 +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,
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        linux-mediatek@lists.infradead.org,
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        chaotian.jing@mediatek.com, cc.chou@mediatek.com,
        jiajie.hao@mediatek.com, alice.chao@mediatek.com
Subject: Re: [PATCH v1] scsi: ufs-mediatek: Enable
 UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL
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References: <20201222072928.32328-1-stanley.chu@mediatek.com>
 <c862866ec97516a7ffb891e5de3d132d@codeaurora.org>
 <1608697172.14045.5.camel@mtkswgap22>
 <c83d34ca8b0338526f6440f1c4ee43dd@codeaurora.org>
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On 2020-12-23 12:41, Can Guo wrote:
> On 2020-12-23 12:19, Stanley Chu wrote:
>> Hi Can,
>> 
>> On Tue, 2020-12-22 at 19:34 +0800, Can Guo wrote:
>>> On 2020-12-22 15:29, Stanley Chu wrote:
>>> > Flush during hibern8 is sufficient on MediaTek platforms, thus
>>> > enable UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL to skip enabling
>>> > fWriteBoosterBufferFlush during WriteBooster initialization.
>>> >
>>> > Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
>>> > ---
>>> >  drivers/scsi/ufs/ufs-mediatek.c | 1 +
>>> >  1 file changed, 1 insertion(+)
>>> >
>>> > diff --git a/drivers/scsi/ufs/ufs-mediatek.c
>>> > b/drivers/scsi/ufs/ufs-mediatek.c
>>> > index 80618af7c872..c55202b92a43 100644
>>> > --- a/drivers/scsi/ufs/ufs-mediatek.c
>>> > +++ b/drivers/scsi/ufs/ufs-mediatek.c
>>> > @@ -661,6 +661,7 @@ static int ufs_mtk_init(struct ufs_hba *hba)
>>> >
>>> >  	/* Enable WriteBooster */
>>> >  	hba->caps |= UFSHCD_CAP_WB_EN;
>>> > +	hba->quirks |= UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL;
>>> >  	hba->vps->wb_flush_threshold = UFS_WB_BUF_REMAIN_PERCENT(80);
>>> >
>>> >  	if (host->caps & UFS_MTK_CAP_DISABLE_AH8)
>>> 
>>> I guess we need it too...
>> 
>> AHHA, if you decide to add this in your platform too later, maybe we
>> could change the way it does: Keep manual flush disabled by default 
>> and
>> remove this quirk.
>> 
> 
> Yeah... I will get back with an answer later.

Hi Stanley,

Do you see any substantial benefit of having fWriteBoosterBufferFlushEn 
disabled?

Thanks,
Can Guo.

> 
> Thanks,
> 
> Can Guo.
> 
>> Thanks,
>> Stanley Chu
>>> 
>>> Change LGTM.
>>> 
>>> Regards,
>>> 
>>> Can Guo.