Re: [PATCH 1/2] wifi: mt76: mt7921: Disable powersaving by default

[James Prestwood]

On 12/13/23 11:27, Mario Limonciello wrote:
> On 12/13/2023 08:45, Ben Greear wrote:
> > On 12/13/23 5:26 AM, Lorenzo Bianconi wrote:
> > > > Mario Limonciello <mario.limonciello@xxxxxxx> writes:
> > > >
> > > > > Several users have reported awful latency when powersaving is enabled
> > > > > with certain access point combinations.
> > > >
> > > > What APs are these exactly? In the past 802.11 Power Save Mode was
> > > > challenging due to badly behaving APs. But nowadays with so many 
> > > > mobile
> > > > devices in the market I would assume that APs work a lot better. It
> > > > would be best to investigate the issues in detail and try to fix 
> > > > them in
> > > > mt76, assuming the bugs are in mt76 driver or firmware.
> > > >
> > > > > It's also reported that the powersaving feature doesn't provide an
> > > > > ample enough savings to justify being enabled by default with these
> > > > > issues.
> > > >
> > > > Any numbers or how was this concluded?
> > > >
> > > > > Introduce a module parameter that would control the power saving
> > > > > behavior.  Set it to default as disabled. This mirrors what some 
> > > > > other
> > > > > WLAN drivers like iwlwifi do.
> > > >
> > > > We have already several ways to control 802.11 power save mode:
> > > >
> > > > * NL80211_CMD_SET_POWER_SAVE (for example used by 'iw set power_save')
> > > >
> > > > * CONFIG_CFG80211_DEFAULT_PS (for kernel level default)
> > > >
> > > > * WIPHY_FLAG_PS_ON_BY_DEFAULT (for the driver to control the 
> > > > default setting)
> > > >
> > > > Adding module parameters as a fourth method sounds confusing so not
> > > > really a fan of this. And the bar is quite high for adding new module
> > > > parameters anyway.
> > >
> > > agree, I think we do not need a new parameter for this, just use the 
> > > current
> > > APIs.
> >
> > Is there a convenient way for a user to make any of those options 
> > above stick through
> > reboots?
> >
> > To me, the ability to set system defaults through reboots is a nice 
> > feature of
> > module options.
> >
> > Thanks,
> > Ben
>
> Some userspace has the ability to do this.  For example in Network 
> Manager:
>
> https://unix.stackexchange.com/questions/595116/wi-fi-powersaving-in-networkmanager 

And recently added to IWD for this very reason, there are no decent ways 
to persist between reboots (except when using NM).

https://git.kernel.org/pub/scm/network/wireless/iwd.git/commit/?id=29edb1626d88bb713db71f7b374d8f24832fd94f

Thanks,

James