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

[James Prestwood <prestwoj@gmail.com>]

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@amd.com> 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