On 23/12/21 22:38, David Mosberger-Tang wrote:

EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe

On Thu, 2021-12-23 at 14:02 +0000, Ajay.Kathat@microchip.com wrote:

quoted

I verified with wpa_supplicant and it seems the power save mode is
working fine. Tested multiple times with wpa_supplicant running. I
didn't observe any issue in entering or exiting the power-save mode with
wpa_supplicant.

Try to verify without wpa_supplicant in your setup to observe if we are
seeing this same results in that case.

It doesn't help me if it works without wpa_supplicant.  I need a
reliable way to have power-savings mode in effect when using
wpa_supplicant.

Okay. In my setup, I observed that PS mode works with and without 
wpa_supplicant. Now tested by following your command sequence.

quoted

With wpa_supplicant, the current consumption is less when PS mode is
enabled but it would be more compared to without wpa_supplicant.

That's not what I'm talking about though.  The problem is that it seems
to be rather erratic whether issuing the iw power_save command makes a
difference in power-consumption.

I fixed my setup so I can directly measure power consumed rather than
just current (power factor matters).  Again, this is for the entire
device (not just WILC1000).

What I find that when power-saving mode is working as expected, the
device uses an average of 1.1W.  When power-saving mode is not working,
power consumption is about 1.4W, or about 300mW higher.

I tried again *without* the patch applied and, as expected, the patch
doesn't really affect this behavior.

After playing with this for a while, I think I found two sequences that
reliably reproduce the difference.

First, on a freshly booted system and with wilc1000-spi autoloaded by
the kernel, try this sequence (copy & paste the commands):

    /usr/sbin/wpa_supplicant -Bs -iwlan0 -c/etc/wpa_supplicant.conf
    sleep 10
    iw dev wlan0 set power_save on

The above yields a power consumption of 1.4W reliably.  The "sleep 10"
doesn't matter here; the behavior is the same with or without it.  I
tried waiting up to 120 seconds with no difference.

I have tested by making the WILC as build-in module to insert driver 
automatically at boot-up. I hope it should be fine. Because I have 
already tested as loadable module earlier.

Below are the number observed
------------------------------ --------------------------
- before starting wpa_supplicant             : ~16.3 mA
- wpa_supplicant started                         : ~40 mA
- PSM on                                                  :  ~6 mA


The 'sleep 10' would have no impact in my setup because I have measured 
the current consumption for wilc1000 chip.

I have shared the screenshot at https://postimg.cc/67S41dkb

Second, on a freshly booted system and with wilc1000-spi autoloaded by
the kernel, try this sequence (copy & paste the commands):

    /usr/sbin/wpa_supplicant -Bs -iwlan0 -c/etc/wpa_supplicant.conf
    sleep 10
    rmmod wilc1000-spi
    modprobe wilc1000-spi
    sleep 10
    iw dev wlan0 set power_save on

The above yields a power consumption of 1.1W reliably.

Can you reproduce this, or, if not, share the power consumption you see
for the two cases?

Second case was verified earlier and also tested by toggle power_save 
mode on/off many times and I observe the numbers are in same range for 
both cases.

Regards,
Ajay