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From: =?utf-8?B?7J207Iq57Z2s?= <sh043.lee@samsung.com>
To: "'Greg KH'" <gregkh@linuxfoundation.org>
Cc: "'Ulf Hansson'" <ulf.hansson@linaro.org>, <linux-mmc@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <avri.altman@wdc.com>,
	<grant.jung@samsung.com>, <jt77.jang@samsung.com>,
	<dh0421.hwang@samsung.com>, <junwoo80.lee@samsung.com>,
	<jangsub.yi@samsung.com>, <cw9316.lee@samsung.com>,
	<sh8267.baek@samsung.com>, <wkon.kim@samsung.com>, <sh043.lee@samsung.com>
In-Reply-To: <2024021528-fretted-sustainer-2ebc@gregkh>
Subject: RE: [PATCH] mmc: sd: Add a variable to check a faulty device
Date: Thu, 15 Feb 2024 20:15:45 +0900
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References: <CGME20240213051332epcas1p1f45d02dc34d1b95ea5608ab779d6b6cc@epcas1p1.samsung.com>
	<20240213051716.6596-1-sh043.lee@samsung.com>
	<CAPDyKFrjZ4jRHAfXsvrEvezuHTxbA3SAniF8CuObyLuW=AUoeA@mail.gmail.com>
	<000001da5faa$d34e1600$79ea4200$@samsung.com>
	<2024021528-fretted-sustainer-2ebc@gregkh>

> -----Original Message-----
> From: Greg KH <gregkh=40linuxfoundation.org>
> Sent: Thursday, February 15, 2024 5:07 PM
> To: =EC=9D=B4=EC=8A=B9=ED=9D=AC=20<sh043.lee=40samsung.com>=0D=0A>=20Cc:=
=20'Ulf=20Hansson'=20<ulf.hansson=40linaro.org>;=20linux-mmc=40vger.kernel.=
org;=0D=0A>=20linux-kernel=40vger.kernel.org;=20avri.altman=40wdc.com;=20gr=
ant.jung=40samsung.com;=0D=0A>=20jt77.jang=40samsung.com;=20dh0421.hwang=40=
samsung.com;=20junwoo80.lee=40samsung.com;=0D=0A>=20jangsub.yi=40samsung.co=
m;=20cw9316.lee=40samsung.com;=20sh8267.baek=40samsung.com;=0D=0A>=20wkon.k=
im=40samsung.com=0D=0A>=20Subject:=20Re:=20=5BPATCH=5D=20mmc:=20sd:=20Add=
=20a=20variable=20to=20check=20a=20faulty=20device=0D=0A>=20=0D=0A>=20On=20=
Thu,=20Feb=2015,=202024=20at=2010:03:45AM=20+0900,=20=EC=9D=B4=EC=8A=B9=ED=
=9D=AC=20wrote:=0D=0A>=20>=20>=20-----Original=20Message-----=0D=0A>=20>=20=
>=20From:=20Ulf=20Hansson=20<ulf.hansson=40linaro.org>=0D=0A>=20>=20>=20Sen=
t:=20Wednesday,=20February=2014,=202024=208:27=20PM=0D=0A>=20>=20>=20To:=20=
Seunghui=20Lee=20<sh043.lee=40samsung.com>=0D=0A>=20>=20>=20Cc:=20linux-mmc=
=40vger.kernel.org;=20linux-kernel=40vger.kernel.org;=0D=0A>=20>=20>=20greg=
kh=40linuxfoundation.org;=20avri.altman=40wdc.com;=0D=0A>=20>=20>=20grant.j=
ung=40samsung.com;=20jt77.jang=40samsung.com;=0D=0A>=20>=20>=20dh0421.hwang=
=40samsung.com;=20junwoo80.lee=40samsung.com;=0D=0A>=20>=20>=20jangsub.yi=
=40samsung.com;=20cw9316.lee=40samsung.com;=0D=0A>=20>=20>=20sh8267.baek=40=
samsung.com;=20wkon.kim=40samsung.com=0D=0A>=20>=20>=20Subject:=20Re:=20=5B=
PATCH=5D=20mmc:=20sd:=20Add=20a=20variable=20to=20check=20a=20faulty=0D=0A>=
=20>=20>=20device=0D=0A>=20>=20>=0D=0A>=20>=20>=20On=20Tue,=2013=20Feb=2020=
24=20at=2006:13,=20Seunghui=20Lee=20<sh043.lee=40samsung.com>=0D=0A>=20wrot=
e:=0D=0A>=20>=20>=20>=0D=0A>=20>=20>=20>=20In=20mobile=20devices,=20suspend=
/resume=20situations=20are=20frequent.=0D=0A>=20>=20>=20>=20In=20the=20case=
=20of=20a=20defective=20SD=20card=20in=20which=20initialization=20fails,=0D=
=0A>=20>=20>=20>=20unnecessary=20initialization=20time=20is=20consumed=20fo=
r=20each=20resume.=0D=0A>=20>=20>=20>=20A=20field=20is=20needed=20to=20chec=
k=20that=20SD=20card=20initialization=20has=20failed=0D=0A>=20>=20>=20>=20o=
n=20the=20host.=20It=20could=20be=20used=20to=20remove=20unnecessary=20init=
ialization.=0D=0A>=20>=20>=0D=0A>=20>=20>=20It's=20not=20clear=20to=20me,=
=20under=20what=20circumstance=20you=20want=20to=20optimize=20for.=0D=0A>=
=20>=20>=0D=0A>=20>=20>=20Is=20the=20SD=20card=20ever=20getting=20properly=
=20initialized=20during=20boot?=0D=0A>=20>=20>=0D=0A>=20>=20>=20Kind=20rega=
rds=0D=0A>=20>=20>=20Uffe=0D=0A>=20>=20>=0D=0A>=20>=20We=20receive=20a=20lo=
t=20of=20reports=20about=20SD=20card=20issues=20in=20the=20market.=0D=0A>=
=20>=20There=20was=20no=20problem=20with=20the=20first=20time=20at=20the=20=
time=20of=20use,=20and=20there=0D=0A>=20are=20many=20cases=20where=20people=
=20recognize=20that=20it=20is=20not=20recognized=20later=20on.=0D=0A>=20In=
=20most=20cases,=20this=20is=20a=20problem=20with=20the=20SD=20card=20itsel=
f.=0D=0A>=20>=0D=0A>=20>=20SD=20card=20users=20cannot=20determine=20whether=
=20or=20not=20an=20SD=20card=20is=20a=20problem,=0D=0A>=20so=20they=20shoul=
d=20be=20guided=20in=20this=20regard.=0D=0A>=20>=20It=20is=20necessary=20to=
=20distinguish=20whether=20the=20SD=20card=20is=20inserted=20but=0D=0A>=20u=
nrecognized=20or=20the=20SD=20card=20itself=20is=20not=20inserted,=20and=20=
if=20there=20is=20a=0D=0A>=20field=20that=20can=20check=20for=20initializat=
ion=20failure,=20it=20will=20facilitate=0D=0A>=20guidance,=20so=20we=20cons=
idered=20the=20patch.=0D=0A>=20>=0D=0A>=20>=20The=20variable's=20usage=20is=
=20expected=20to=20be=20used=20through=20the=20sysfs=20node=20in=0D=0A>=20t=
he=20vendor=20module.=0D=0A>=20=0D=0A>=20What=20=22vendor=20module=22?=20=
=20You=20need=20to=20include=20all=20of=20the=20needed=20code=20here=0D=0A>=
=20please.=0D=0A>=20=0D=0A>=20thanks,=0D=0A>=20=0D=0A>=20greg=20k-h=0D=0A=
=0D=0AThis=20only=20purpose=20of=20this=20variable=20is=20to=20identify=20a=
=20faulty=20card=20on=20host=20side.=0D=0A=0D=0AIn=20the=20past,=20we=20can=
=20identify=20that=20the=20card=20is=20inserted=20or=20not=20with=20reading=
=20get_cd()=20function.=0D=0ABut=20now,=20most=20mobile=20devices=20use=20h=
ybrid=20type=20of=20SD=20card=20tray.=0D=0AIf=20the=20tray=20is=20inserted,=
=20the=20return=20value=20of=20get_cd=20is=20the=20same=20whatever=20the=20=
SD=20card=20is=20inserted=20or=20not.=0D=0AIt=20can=20help=20us=20diagonose=
=20the=20status=20of=20a=20SD=20card=20as=20well.=0D=0A=0D=0AHere=20is=20th=
e=20example=20of=20usage.=0D=0A=0D=0Astatic=20ssize_t=20status_show(struct=
=20device=20*dev,=0D=0A=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20stru=
ct=20device_attribute=20*attr,=20char=20*buf)=0D=0A=7B=0D=0A=20=20=20=20=20=
=20=20=20struct=20mmc_host=20*host=20=3D=20dev_get_drvdata(dev);=0D=0A=20=
=20=20=20=20=20=20=20struct=20mmc_card=20*card=20=3D=20host->card;=0D=0A=20=
=20=20=20=20=20=20=20char=20*status=20=3D=20NULL;=0D=0A=0D=0A=20=20=20=20=
=20=20=20=20if=20(card)=0D=0A=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=
=20status=20=3D=20mmc_card_readonly(card)=20?=20=22PERMWP=22=20:=20=22NORMA=
L=22;=0D=0A=20=20=20=20=20=20=20=20else=0D=0A=20=20=20=20=20=20=20=20=20=20=
=20=20=20=20=20=20status=20=3D=20host->init_failed=20?=20=22INITFAIL=22=20:=
=20=22NOCARD=22;=0D=0A=0D=0A=20=20=20=20=20=20=20=20return=20sysfs_emit(buf=
,=20=22%s=5Cn=22,=20status);=0D=0A=7D=0D=0A=0D=0AAs=20for=20the=20sysfs=20n=
ode,=20it=20should=20keep=20the=20path=20of=20node=20with=20or=20without=20=
the=20SD=20card.=0D=0AThat's=20why=20I=20mention=20the=20vendor=20module.=
=0D=0A=0D=0AIf=20I=20need=20to=20update=20the=20commit's=20comment,=20I'll=
=20fix=20it.=0D=0AIf=20someone=20has=20the=20better=20idea(e.g.=20code,=20c=
omment),=20please=20suggest=20it.=0D=0A=0D=0AThank=20you=20for=20reviewing=
=20this.=0D=0ASeunghui=20Lee.=0D=0A=0D=0A=0D=0A