HowTo enable the power saving functionality(1).doc

A Brief Introduction to RTL8192C driver Power Saving

1.) RTL8192C consists of two power modes:

A). Minimum Power Saving mode.

In this PS mode, RTL8192C wakes up every beacon interval. Figure 1 shows the RTL8192C power consumption under Minimum Power Saving mode.

Figure 1. Minimum Power Saving mode (Associated idle)

B). Maximum Power Saving mode:   

When driver be set to maximum power saving mode, which means RTL8192C wake up to receive beacon when DTIM count of beacon is zero.

If DTIM period of beacon is 3 RTL8192C would wake up every 3 bacon interval. Figure 2 illustrates RTL8192C power consumption under Maximum Power Saving mode:

Figure 2. Maximum Power Saving mode (Associated idle)

2.) The following document will describe the way to let this driver to enable the power saving functionality.

===========================================================

                            A-1.) Power Saving Mode – by modify Makefile

===========================================================

You can easy set the power saving to Min-PS (rtw_power_mgnt=1) by modify the CONFIG_POWER_SAVING to y, at the line 20 of Makefile file.

Ex:

CONFIG_POWER_SAVING               =               y

===========================================================

                            A-2.) Power Saving Mode – by change load-time parameters

===========================================================

(1) In order to enter PS Mode, you need to add the parameter of "rtw_power_mgnt=1" when executing "insmod 8192cu.ko" :

                            $>insmod 8192cu.ko rtw_power_mgnt=1

                            or

                            $>insmod 8192cu.ko rtw_power_mgnt=2

(2)Parameter Notes:                           

                            rtw_power_mgnt=1 ;//enable PS, MIN_PS Mode

                            rtw_power_mgnt=2 ;//enable PS, MAX_PS Mode
 

===========================================================

                            B-1.) USB Autosuspend - by modify Makefile

===========================================================

You can turn on USB autosuspend function by modify the CONFIG_USB_AUTOSUSPEND to y, at the line 21 of Makefile file.

Ex:

CONFIG_USB_AUTOSUSPEND               =               y

===========================================================

                            B-1.) USB Autosuspend - by change load-time parameters

===========================================================

(1) In PS mode, you can turn on or turn off the USB autosuspend functionality by adding the following parameter.             

              $>insmod 8192cu.ko rtw_power_mgnt=1 enusbss = 1

              or

              $>insmod 8192cu.ko rtw_power_mgnt=1 enusbss = 0

              or

$>insmod 8192cu.ko rtw_power_mgnt=2 enusbss = 1

              or

              $>insmod 8192cu.ko rtw_power_mgnt=2 enusbss = 0

(2)Parameter Notes:

                            enusbss = 1; // enable USB autosuspend

enusbss = 0; // default, disable USB autosuspend

===========================================================

                            C-1.) RF on/off detection – by modify Makefile

===========================================================

You can turn on this function by modify the CONFIG_HW_PWRP_DETECTION to y, at the line 22 of Makefile file.

Ex:

CONFIG_HW_PWRP_DETECTION               =               y

===========================================================

                            C-2.) RF on/off detection – by change load-time parameters

===========================================================

(1) If you want turn on this function in load time, you need to add the parameter of " hwpwrp_detect =1" when executing "insmod 8192cu.ko" :

                            $>insmod 8192cu.ko hwpwrp_detect =1             

(2)Parameter Notes:                           

                            hwpwrp_detect =1 ;//enable hw power pin detection

                            hwpwrp_detect =0 ;//disable hw power pin detection
 

3.) Power consumption example