linux-kernel - RE: [PATCH v2 RFC 3/9] wifi: rtw88: mac: Support SDIO specific bits in the power on sequence

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Message-ID: <8404a75a4c194fa79f8e24a9731c3ce3@realtek.com>
Date:   Tue, 14 Mar 2023 00:48:09 +0000
From:   Ping-Ke Shih <pkshih@...ltek.com>
To:     Martin Blumenstingl <martin.blumenstingl@...glemail.com>
CC:     "linux-wireless@...r.kernel.org" <linux-wireless@...r.kernel.org>,
        Yan-Hsuan Chuang <tony0620emma@...il.com>,
        Kalle Valo <kvalo@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
        Chris Morgan <macroalpha82@...il.com>,
        "Nitin Gupta" <nitin.gupta981@...il.com>,
        Neo Jou <neojou@...il.com>,
        Jernej Skrabec <jernej.skrabec@...il.com>
Subject: RE: [PATCH v2 RFC 3/9] wifi: rtw88: mac: Support SDIO specific bits in the power on sequence



> -----Original Message-----
> From: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
> Sent: Tuesday, March 14, 2023 4:12 AM
> To: Ping-Ke Shih <pkshih@...ltek.com>
> Cc: linux-wireless@...r.kernel.org; Yan-Hsuan Chuang <tony0620emma@...il.com>; Kalle Valo
> <kvalo@...nel.org>; Ulf Hansson <ulf.hansson@...aro.org>; linux-kernel@...r.kernel.org;
> netdev@...r.kernel.org; linux-mmc@...r.kernel.org; Chris Morgan <macroalpha82@...il.com>; Nitin Gupta
> <nitin.gupta981@...il.com>; Neo Jou <neojou@...il.com>; Jernej Skrabec <jernej.skrabec@...il.com>
> Subject: Re: [PATCH v2 RFC 3/9] wifi: rtw88: mac: Support SDIO specific bits in the power on sequence
> 
> Hello Ping-Ke,
> 
> On Mon, Mar 13, 2023 at 10:05 AM Ping-Ke Shih <pkshih@...ltek.com> wrote:
> [...]
> > >         pwr_seq = pwr_on ? chip->pwr_on_seq : chip->pwr_off_seq;
> > >         ret = rtw_pwr_seq_parser(rtwdev, pwr_seq);
> > > -       if (ret)
> > > -               return ret;
> > > +
> > > +       if (rtw_hci_type(rtwdev) == RTW_HCI_TYPE_SDIO)
> > > +               rtw_write32(rtwdev, REG_SDIO_HIMR, imr);
> > >
> > >         if (pwr_on)
> > >                 set_bit(RTW_FLAG_POWERON, rtwdev->flags);
> >
> > If failed to power on, it still set RTW_FLAG_POWERON. Is it reasonable?
> That sounds very reasonable to me!

Let me clear here more.

Consider a use case:
1. Initially, it enters this function with pwr_on = true, and RTW_FLAG_POWERON is unset.
2. rtw_pwr_seq_parser() return error, so power state is uncertain.
3. Unconditionally, set RTW_FLAG_POWERON.

rtw_mac_power_on() will try to power off/on once again if it fails, so
in step 3 setting RTW_FLAG_POWERON only if rtw_pwr_seq_parser() returns 0
can have the same values as step 1, when it retries to power on.

Honestly, we don't have perfect error handle for error of rtw_pwr_seq_parser(),
but still want to make things easier understand.

> 
> > Did you meet real problem here?
> >
> > Maybe, here can be
> >
> >          if (pwr_on && !ret)
> >                  set_bit(RTW_FLAG_POWERON, rtwdev->flags);
> I can't remember any issue that I've seen. I'll verify this at the end
> of the week (until then I am pretty busy with my daytime job) and then
> go with your suggestion.

Thanks. Wait for you.

> Thanks again as always - your feedback is really appreciated!
> 
> Also thank you for commenting on the other patches. I'll take a closer
> look at your feedback at the end of the week and send another version
> of this series.
> 

I also thank you for cooking these patches voluntarily for people who
can use their own wifi happily. :-)

Ping-Ke