Re: RFC: wilc1000 module parameter to disable chip sleep

On Thu, 2021-12-09 at 09:20 +0000, Ajay.Kathat@microchip.com wrote:

On 09/12/21 00:20, David Mosberger-Tang wrote:

The "chip_wakeup" & "chip_allow_sleep" API's are required to configure 
the wake-up registers in wilc. These registers must be configured 
correctly when the power save mode is enabled.

I see.

quoted

Here is what I see: on a system configured for minimum power consumption
(all unnecessary daemons disabled, Ethernet unplugged) I measured 1,180 mW
when the WILC chip is in RESET (the ENABLE pin is always high on our
platform).

With the wilc1000-spi/wilc1000 modules loaded and the WILC chip
running but without being associated with a WLAN network, measured
power consumption was 1,460 mW, regardless of whether chip sleep was
enabled or disabled.

Did you test by enabling the power-save mode with "wpa_supplicant" or 
using "iw" command. For power consumption measurement, please try by 
disabling the PSM mode.

No, I have not played with power-saving mode.  There are some disconcerting
messages when turning PSM on:

[ 1764.070375] wilc1000_spi spi1.0: Failed cmd, cmd (ca), resp (00)
[ 1764.076403] wilc1000_spi spi1.0: Failed cmd, read reg (000013f4)...

The driver does still work, but occasionally, I get long streams of these
messages, sometimes it gets to the point where there are so many that the
watchdog timer ends up rebooting the system.

The chip-sleep code is needed to configure the registers properly for 
wilc and not using these sequence would have impact on sending the data 
to wilc, especially when the PS mode is enabled.

How about something along the patch below then?

With this patch, I see the following iperf3 performance (120 second average):

PSM on:
[  4]   0.00-120.00 sec  47.6 MBytes  3.33 Mbits/sec    0             sender

PSM off:
[  4]   0.00-120.00 sec   201 MBytes  14.0 Mbits/sec   12             sender

In terms of power consumption:

   baseline                : 1.2 W
   PSM on, idle            : 1.2 W
   PSM on, TX @ 3.33 Mbps  : 1.7 W
   PSM off, idle           : 1.5 W
   PSM off, TX @ 14.0 Mbps : 2.4 W

  --david