MIME-Version: 1.0
References: <20181217164207.20081-1-tony@atomide.com> <CAPDyKFoLnNWsBfaUwqwL31J=zb0UOQjXUKi7Sj0AUsnNoC6bYg@mail.gmail.com>
 <20181218155439.GB6707@atomide.com> <CAPDyKFr2xx6fmdgjd10C1jekWg-yZPk32fGWEPO2PyexjofJ1A@mail.gmail.com>
 <20181220231401.GG6707@atomide.com> <c22e2ab61b494ea0852c0f4654fef92d@ti.com>
 <20181223160226.GK6707@atomide.com> <CAPDyKFoEOGACs4Wnm7UgKab2b1-7+v8+31DpC+p=8XxcQhSpcQ@mail.gmail.com>
 <20181228195903.GX6707@atomide.com> <CAPDyKFq9XmRueJEFKVb03hqLuoB84TGjrdvEjre46ezYbk_wgw@mail.gmail.com>
 <20190107151849.GC5544@atomide.com> <87k1jgsaze.fsf@kamboji.qca.qualcomm.com>
In-Reply-To: <87k1jgsaze.fsf@kamboji.qca.qualcomm.com>
From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Mon, 14 Jan 2019 14:47:31 +0100
Message-ID: <CAPDyKFrYk87AwpHd5B06quGQAtfPYRHMD-9-2WzR=7Y=5Oog2A@mail.gmail.com>
Subject: Re: [EXTERNAL] Re: [PATCH] wlcore: Fix bringing up wlan0 again if
 powered down briefly
To:     Kalle Valo <kvalo@codeaurora.org>
Cc:     Tony Lindgren <tony@atomide.com>, "Reizer, Eyal" <eyalr@ti.com>,
        KISHON VIJAY ABRAHAM <kishon@ti.com>,
        "Mishol, Guy" <guym@ti.com>,
        "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        linux-omap <linux-omap@vger.kernel.org>,
        Anders Roxell <anders.roxell@linaro.org>,
        John Stultz <john.stultz@linaro.org>,
        Ricardo Salveti <rsalveti@rsalveti.net>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

On Mon, 7 Jan 2019 at 17:12, Kalle Valo <kvalo@codeaurora.org> wrote:
>
> Tony Lindgren <tony@atomide.com> writes:
>
> > * Ulf Hansson <ulf.hansson@linaro.org> [190102 12:02]:
> >>
> >> However, if this is about an out-of-band IRQ line, instead of using
> >> the SDIO IRQs on DAT1, I think management of that, belongs in the wlan
> >> (or gpiochip) layers.
> >
> > Yes this can be handled at the gpiochip layer.
> >
> >> We have to distinguish if "down" has a strict requirement to power off
> >> the wlan-chip.
> >>
> >> For example, in "flight mode", is it okay to leave the wlan chip
> >> powered on and thus potentially also having its radio part active?
> >
> > I don't know. If unsure, we should at least have that possibility
> > available for future versions if needed. It might also help a bit
> > with PM measurements :)
>
> I don't know if there are any written rules but I have preferred that in
> wireless drivers "ifconfig down" means that all power is turned off on
> the device, at least this way user space can achive maximum power
> savings. And there's also a simple way to start the firmware from clean
> state, we all know how buggy firmwares are so I think that's important
> as well.

Alright, I buy this! I am going to have a look to see how we can
accomplish this in the best way, but I need some more time before I
can post something.

In the meantime, let's go with Tony's suggestion to fix the
regression. I am about to post a patch.

Kind regards
Uffe