Hi Sebastian, > -----Original Message----- > From: Sebastian Andrzej Siewior [mailto:sebastian@xxxxxxxxxxxxx] > Sent: Thursday, September 17, 2009 9:12 AM > To: Andrey Yurovsky > Cc: Bing Zhao; Dan Williams; Amitkumar Karwar; linux-wireless@xxxxxxxxxxxxxxx; libertas- > dev@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH] libertas: Add auto deep sleep support for SD8385/SD8686/SD8688 > > * Andrey Yurovsky | 2009-09-16 13:47:48 [-0700]: > > >> Some information (such as the interface name and path) in README file is out of date. We just > copy-and-paste it for the new deepsleep command. We need a separate patch to clean up the REAME file > and keep it up to date. > > > >Ok. Either way, this is another out-of-band interface (regardless of > >if it's debugfs or sysfs). That said, I believe that debugfs should > >be used for debugging, not for configuring driver/device features like > >these. > I agree on this. Debugfs is for debug only and should stay that way. > What do other driver in regard to this? I hardly belive that the > libertas driver is the only "deep sleep" user. The debugfs interface has already been used for configuring some other parameters in libertas driver. Choosing a different way for deep sleep configuration doesn't make sense to me. > > >>> Deep sleep seems to pretty much "turn off" the wifi card (as far as > >>> the user is concerned) so how about a simpler approach: enter deep > >>> sleep when the interface is brought down (ifconfig wlanN down) and > >>> exit deep sleep when it's brought up. ?Do this only when deep sleep is > >>> supported/possible. ?Alternately, maybe this belongs as an rfkill > >>> feature? > >> > >> Entering/exiting deep sleep doesn't have to depend on wlanN interface's up and down. User can > still put the chip into sleep when wlanN is up. And, with auto deep sleep feature, the driver > automatically wakes the chip up for sending user commands (for example, scan) and put the chip back > to sleep after certain time period of inactivity. The deepsleep command through debugfs interface > provides the flexibility of deep sleep options. > >> > >> The rfkill shuts down the RF transmitter of the device but most of other modules may be still > functioning. The deep sleep shuts down most of the modules (including the RF) on the chip to save as > much power as possible. > > > >It seems that when the device is in deep sleep, it's effectively > >"turned off" as far as the user is concerned. That seems really > >similar to "ifconfig down" or rfkill, does the user really care about > >anything beyond that? I understand that it's possible to control this > >feature independently of either of those functions, but is it ever > >necessary? If not, it would be great to just integrate it into one > >(or both) of these already standard network interface semantics and > >not introduce a whole new configuration parameter. > > iwconfig has an interface for this I think: > |interface power {period N|timeout N|saving N|off} > > From what I see in the man page it covers pretty much what you wrote in > the Readme file. So it looks like like there is your flexible interface > you've been looking for :) Unfortunately, the "iwconfig wlanN power" command is used for ieee power saving mode in the driver. Regards, Bing > > > -Andrey > > > >> Regards, > >> > >> Bing > > Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
