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From:   =?UTF-8?B?6auY5Lil5Yev?= <gaoyankaigeren@gmail.com>
Date:   Tue, 11 Oct 2022 19:53:01 +0800
Message-ID: <CAFN68yVajOkV++gCp-y1+SD5VOKLgUeBhfgskrJZOX5dfGi07A@mail.gmail.com>
Subject: Re: [PATCH] ufs: core: Disable auto h8 before ssu
To:     Avri Altman <Avri.Altman@wdc.com>
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Bart Van Assche <bvanassche@acm.org>,
        "James E . J . Bottomley" <jejb@linux.ibm.com>,
        Bean Huo <beanhuo@micron.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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Dear Avri
  Unisoc reports resume fail on UFS(micron FS164) during suspend/resume tes=
t.
  We check host inserts auto H8 enter/exit event between SSU sleep
command and H8 enter command in runtime suspend .
  Asfollows: SSU Sleep command --> auto H8 enter --> auto H8 exit -->
H8 enter --> idle 2ms --> VCC off.
  However device AQL FW can=E2=80=99t enter LPM within 2ms after second H8
enter command.
  FW already enter LPM after receive auto H8 enter command , Next auto
H8 exit command will trigger FW exit from LPM, it need take over 10ms,
and FW can=E2=80=99t enter
  LPM again after second H8 enter command until device complete exit
from LPM. So disable auto h8 before ssu is a reasonable solution to
solve it.
  Hynix also has similar request.

Avri Altman <Avri.Altman@wdc.com> =E4=BA=8E2022=E5=B9=B410=E6=9C=8811=E6=97=
=A5=E5=91=A8=E4=BA=8C 15:07=E5=86=99=E9=81=93=EF=BC=9A
>
> > From: Ten Gao <ten.gao@unisoc.com>
> >
> > Ensure auto h8 will not hit dme h8,and there won't be two h8 in a row a=
fter
> > ssu.
> I don't think the hw should do that.
> Can you please share on which platform/host controller did you observe th=
is?
>
> Thanks,
> Avri
> >
> > Signed-off-by: Ten Gao <ten.gao@unisoc.com>
> > ---
> >  drivers/ufs/core/ufshcd.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c inde=
x
> > a202d7d5240d..42f93648d796 100644
> > --- a/drivers/ufs/core/ufshcd.c
> > +++ b/drivers/ufs/core/ufshcd.c
> > @@ -4256,6 +4256,14 @@ void ufshcd_auto_hibern8_update(struct ufs_hba
> > *hba, u32 ahit)  }  EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update);
> >
> > +void ufshcd_auto_hibern8_disable(struct ufs_hba *hba) {
> > +       if (!ufshcd_is_auto_hibern8_supported(hba))
> > +               return;
> > +
> > +       ufshcd_writel(hba, 0, REG_AUTO_HIBERNATE_IDLE_TIMER); }
> > +
> >  void ufshcd_auto_hibern8_enable(struct ufs_hba *hba)  {
> >         if (!ufshcd_is_auto_hibern8_supported(hba))
> > @@ -9036,6 +9044,8 @@ static int __ufshcd_wl_suspend(struct ufs_hba
> > *hba, enum ufs_pm_op pm_op)
> >         if (ret)
> >                 goto enable_scaling;
> >
> > +       ufshcd_auto_hibern8_disable(hba);
> > +
> >         if (req_dev_pwr_mode !=3D hba->curr_dev_pwr_mode) {
> >                 if (pm_op !=3D UFS_RUNTIME_PM)
> >                         /* ensure that bkops is disabled */
> > --
> > 2.17.1
>