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From:   =?UTF-8?B?6auY5Lil5Yev?= <gaoyankaigeren@gmail.com>
Date:   Fri, 14 Oct 2022 10:44:50 +0800
Message-ID: <CAFN68yVdwrECaDvNuok_4V-54UZUJU9+dn5icaiPdj6BXEZuVA@mail.gmail.com>
Subject: Re: [PATCH] ufs: core: Disable auto h8 before ssu
To:     Bean Huo <huobean@gmail.com>
Cc:     Avri Altman <Avri.Altman@wdc.com>,
        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 Bean
we can choose one of two h8 for sure, and we chosed auto h8 during sys acti=
ve.
when ufs suspend/resume, ufshcd_link_state_transtion will send DME h8
enter/exit always.
that's why the above sequence show up.
" UFSHCI has idle time before bringing Link into hibern8 mode, " I
think  ufs put the link to h8 during the time

Bean Huo <huobean@gmail.com> =E4=BA=8E2022=E5=B9=B410=E6=9C=8812=E6=97=A5=
=E5=91=A8=E4=B8=89 22:25=E5=86=99=E9=81=93=EF=BC=9A
>
> On Tue, 2022-10-11 at 19:53 +0800, =E9=AB=98=E4=B8=A5=E5=87=AF wrote:
> > Dear Avri
> >   Unisoc reports resume fail on UFS(micron FS164) during
> > suspend/resume test.
> >   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.
>
>
> Hi gaoyan,
>
> The above sequence confuses me. UFSHCI has idle time before bringing
> Link into hibern8 mode, do you know what the settings are?
>
> Also, if auto-hibern8 is supported, in this case, the host-side SW
> should not send manual hibern8. If this is an issue to all UFS or
> UFSHCI, we should disable manual hibern8 if auto-hibern8 is enabled. or
> let customer to choose one of two.
>
>
> Kind regards,
> Bean