Re: power off ath0: <Atheros AR946x/AR948x>

Lars Engels <[email protected]> Tue, 13 Jan 2015 10:13:37 +0100

Newsgroups	gmane.os.freebsd.devel.mobile
Message-ID	<[email protected]>

On Mon, Jan 12, 2015 at 11:20:07AM -0800, Adrian Chadd wrote:
> On 12 January 2015 at 08:56, Warner Losh <[email protected]> wrote:
> >
> >> On Jan 12, 2015, at 9:54 AM, John Baldwin <[email protected]> wrote:
> >>
> >> On 1/11/15 3:05 AM, Matthias Apitz wrote:
> >>>
> >>> Hello,
> >>>
> >>> Is there a way to completely power-off the Wifi chip in my Acer C720?
> >>> I tried 'ifconfig ath0 down' which saves around 20 mA. But the LED stays
> >>> on, which let me think it is still someow on-air.
> >>
> >> Not yet.  You could try setting the tunable to disable power for PCI
> >> devices without a driver and not include 'ath' in your kernel config.  I
> >> will (soon) commit a new 'devctl' tool to HEAD that would let you do
> >> 'devctl suspend ath0' to do this.
> >
> > I’d love to see this tied into the forthcoming work on PCIe hot plug as well,
> > which is one way to power off the slot. But that work seems to be stalled…
> 
> Right. So, the driver in -HEAD should be powering off almost all of
> the chip when no vap (ie, wlanX) is active. The only parts of the chip
> that stay on is the PCIe PHY and the GPIO/RTC block. AFAIK we don't
> support PCIe power save state management at the moment, so we can't
> keep the PCIe PHY off.
> 
> But yeah, most of the chip is off. The chip doesn't take all that much
> power unless it's actively transmitting/receiving. The LEDs are on
> because the GPIO block is on and it's likely holding the LED up.

Is that only true for this chip, all ath ones or even all wireless
devices?

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