linux-kernel - Re: [PATCH V2] wlcore: sdio: Fixup power on/off sequence

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Message-ID: <20190118154934.GW5544@atomide.com>
Date:   Fri, 18 Jan 2019 07:49:34 -0800
From:   Tony Lindgren <tony@...mide.com>
To:     Kalle Valo <kvalo@...eaurora.org>
Cc:     Anders Roxell <anders.roxell@...aro.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Eyal Reizer <eyalr@...com>, linux-wireless@...r.kernel.org,
        Ricardo Salveti <rsalveti@...lveti.net>,
        Kishon Vijay Abraham I <kishon@...com>,
        John Stultz <john.stultz@...aro.org>,
        Jan Kiszka <jan.kiszka@....de>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-omap@...r.kernel.org
Subject: Re: [PATCH V2] wlcore: sdio: Fixup power on/off sequence

* Kalle Valo <kvalo@...eaurora.org> [190118 15:37]:
> Anders Roxell <anders.roxell@...aro.org> writes:
> 
> > On Wed, 16 Jan 2019 at 16:43, Tony Lindgren <tony@...mide.com> wrote:
> >>
> >> * Ulf Hansson <ulf.hansson@...aro.org> [190116 11:37]:
> >> > During "wlan-up", we are programming the FW into the WiFi-chip. However,
> >> > re-programming the FW doesn't work, unless a power cycle of the WiFi-chip
> >> > is made in-between the programmings.
> >> >
> >> > To conform to this requirement and to fix the regression in a simple way,
> >> > let's start by allowing that the SDIO card (WiFi-chip) may stay powered on
> >> > (runtime resumed) when wl12xx_sdio_power_off() returns. The intent with the
> >> > current code is to treat this scenario as an error, but unfortunate this
> >> > doesn't work as expected, so let's fix this.
> >> >
> >> > The other part is to guarantee that a power cycle of the SDIO card has been
> >> > completed when wl12xx_sdio_power_on() returns, as to allow the FW
> >> > programming to succeed. However, relying solely on runtime PM to deal with
> >> > this isn't sufficient. For example, userspace may prevent runtime suspend
> >> > via sysfs for the device that represents the SDIO card, leading to that the
> >> > mmc core also keeps it powered on. For this reason, let's instead do a
> >> > brute force power cycle in wl12xx_sdio_power_on().
> >> >
> >> > Fixes: 728a9dc61f13 ("wlcore: sdio: Fix flakey SDIO runtime PM handling")
> >> > Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
> >> > ---
> >> >
> >> > Changes in v2:
> >> >       - Keep the SDIO host claimed when calling mmc_hw_reset().
> >> >       - Add a fixes tag.
> >>
> >> This v2 version works for me as tested with:
> >>
> >> # while [ 1 ]; do ifconfig wlan0 down; ifconfig wlan0 up; done
> >> [  181.364990] wlcore: down
> >> [  182.116424] wlcore: firmware booted (Rev 6.3.10.0.141)
> >> [  182.151641] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
> >> [  182.166778] wlcore: down
> >> [  182.773132] wlcore: firmware booted (Rev 6.3.10.0.141)
> >> [  182.811096] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
> >> ...
> >>
> >> Thanks for fixing this issue properly, and feel free to add:
> >>
> >> Tested-by: Tony Lindgren <tony@...mide.com>
> >
> > Tested-by: Anders Roxell <anders.roxell@...aro.org>
> >
> > I tested it on a hikey-6220, and it worked.
> 
> So what's the conclusion, can I take this patch? I see that this didn't
> help with Jan but as Tony and Anders provided positive test results I'm
> inclined to take this now and Jan's problem can be fixed with another
> patch. Do everyone agree?

Sounds good to me, seems like there is another separate issue
lurking around somewhere.

Regards,

Tony