Set "disabled" PM at reset, provide PM constants and better documentation

[jepler]

Sets the 0x00a11140 power saving mode at reset time, which is called PM_DISABLED.

The following PM constants are provided:

cyw43.PM_DISABLED    = 0xa11140
cyw43.PM_AGGRESSIVE  = 0xa11c82
cyw43.PM_STANDARD    = 0xa11142
cyw43.PM_PERFORMANCE = 0x111022

"STANDARD" is what was called "DEFAULT" in cyw43 documentation, except we're overriding the default.

Closes: #6958 (pending testing from @anecdata)

[anecdata]

Based on a couple of days of uP testing, and today with CP, I think this is the way to go, at least for now. Connections will be more reliable, and users will have less grief.

I've been running side-by-side power modes 0 and 2 for a couple of hours based on the prior merge (automatically re-connecting to the AP after an OSError: 2), and the 0 (power-save OFF) has been successively doing requests every 10 minutes without any disconnections or failures. The 2 (prior PR, and uP, default power save) output is:

Connected? 192.168.6.199
2022-09-30T12:26:15-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
2022-09-30T12:36:19-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
2022-09-30T12:46:22-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T12:56:42-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
2022-09-30T13:06:46-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
2022-09-30T13:16:51-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T13:27:12-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T13:37:34-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T13:47:55-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T13:58:16-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T14:08:37-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T14:18:58-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T14:29:19-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'
[Errno 2] No such file/directory
Connected? 192.168.6.199
2022-09-30T14:39:40-05:00 600 200 OK b'This is a test of Adafruit WiFi!\nIf you can read this, its working :)'

Frequent OSError, but recoverable with reconnection to the AP. I'll restest the modes with artifacts from this PR when available, and let it go overnight or longer. But I'm good with this approach. Thank you!

[jepler]

I think maybe this doesn't do its intended purpose, because cyw43_arch_enable_sta_mode calls cyw43_wifi_set_up which calls cyw43_wifi_pm. So you can't set the PM mode before putting the wifi up!

[anecdata]

Is that wlan.activate(True) in uP? Maybe default it or an extra keyword arg added to wifi.radio.start_station() or wifi.radio.connect() (and wifi.radio.start_ap()), or some such.

[jepler]

My plan is to keep the value given to set_power_management and re-enforce it when bringing up the interface.

[anecdata]

I think maybe this doesn't do its intended purpose, because cyw43_arch_enable_sta_mode calls cyw43_wifi_set_up which calls cyw43_wifi_pm. So you can't set the PM mode before putting the wifi up!

In uP, the pm config is a method on the network.WLAN which had already been activated. In my CP testing above (and continuing consistent with that report), results may be depending on the fact that they both started with a reload not a reset.

[jepler]

Updated version maybe sets power management off by default as intended.

[anecdata]

Looking good after 60 minutes. Hard-reset, then requests at 10-minute intervals. The board running the new CircuitPython default (no power-save; no calls to cyw43.set_power_management()) has had no disconnections.

[dhalbert]

@jepler Could you fix the two typos I noted above, and possibly address the other comment above?

[jepler]

Done @dhalbert

[dhalbert]

Ready for merge after this? I can stop the unnecessary rebuilds, since this is only a doc change.

[jepler]

Yes I think it's ready!