Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: WhjiX1WOv1y6GtRcEaEA53d19pcSWhrCx3VNIdfoRlOSxLdgMrYoXj5ysN8zRXZd0K92rJmzLI
 m2C4nrJMv5JBQ/FlZz1vYRlv4jo11Fmvrn2aSX7iJibpDdPnDVeMUiOHh8oiYFbtE4oXyTCdb0
 aQpEr8pFCWV3TjUBiLjuvnwGwZn79kByb2rr2VAobTAZ6UXX709BbkvF0fI4cp9nWeHVhoAfaa
 HEmn4mQ73Tm1kpaa2yTlFoza7PH+iMG75v+UpzbtVbDRuYCa78T4jwgYkVH8b3bVZuzxn/qqAR
 K+0=
From:   Avri Altman <Avri.Altman@wdc.com>
To:     Can Guo <cang@codeaurora.org>,
        Stanley Chu <stanley.chu@mediatek.com>
CC:     "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
        "alim.akhtar@samsung.com" <alim.akhtar@samsung.com>,
        "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
        "beanhuo@micron.com" <beanhuo@micron.com>,
        "asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
        "matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
        "bvanassche@acm.org" <bvanassche@acm.org>,
        "linux-mediatek@lists.infradead.org" 
        <linux-mediatek@lists.infradead.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kuohong.wang@mediatek.com" <kuohong.wang@mediatek.com>,
        "peter.wang@mediatek.com" <peter.wang@mediatek.com>,
        "chun-hung.wu@mediatek.com" <chun-hung.wu@mediatek.com>,
        "andy.teng@mediatek.com" <andy.teng@mediatek.com>,
        "chaotian.jing@mediatek.com" <chaotian.jing@mediatek.com>,
        "cc.chou@mediatek.com" <cc.chou@mediatek.com>,
        "jiajie.hao@mediatek.com" <jiajie.hao@mediatek.com>,
        "alice.chao@mediatek.com" <alice.chao@mediatek.com>
Subject: RE: [PATCH v1] scsi: ufs-mediatek: Enable
 UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL
Thread-Topic: [PATCH v1] scsi: ufs-mediatek: Enable
 UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL
Thread-Index: AQHW2DQ3JDYDYaEKR0iGb34jWf7AcqoC/HmAgAEYvgCAAAYJAIAAMzzQ
Date:   Wed, 23 Dec 2020 07:47:10 +0000
Message-ID: <DM6PR04MB657598535F633F59A1DB1F22FCDE0@DM6PR04MB6575.namprd04.prod.outlook.com>
References: <20201222072928.32328-1-stanley.chu@mediatek.com>
 <c862866ec97516a7ffb891e5de3d132d@codeaurora.org>
 <1608697172.14045.5.camel@mtkswgap22>
 <c83d34ca8b0338526f6440f1c4ee43dd@codeaurora.org>
In-Reply-To: <c83d34ca8b0338526f6440f1c4ee43dd@codeaurora.org>
Accept-Language: en-US
Content-Language: en-US
wdcipoutbound: EOP-TRUE
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: f7e37239-fa4b-435c-b403-08d8a716f451
X-MS-Exchange-CrossTenant-originalarrivaltime: 23 Dec 2020 07:47:10.1755
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: b61c8803-16f3-4c35-9b17-6f65f441df86
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: aNF0P6aUAHwZ6USHBBiRysJZXEeLwh1UJlY1XQRUF2LZETNXNlvewNkfEX6d6x+hpLgrA9aMg8qSYU5Rt63irg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR04MB5820
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

>=20
> 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 |=3D UFSHCD_CAP_WB_EN;
> >> > +  hba->quirks |=3D UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL;
> >> >    hba->vps->wb_flush_threshold =3D
> 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.
Ack on that.
I never understood why it was needed in the first place.
Maybe just remove it, and allow to perform explicit flush from sysfs.

Thanks,
Avri
> >
>=20
> Yeah... I will get back with an answer later.