Native Development

[oddboy]

Hi,

trying to get wifi_set_sta_power() work on NDK 10.0.9.386.

when i try to call it, i get "Permissioned Denied" (according to errno).

is the wifi_service (wifi_service.h) working in this version of the NDK?

the code is pretty simple.. 

int setWifiStatus(bool status) {
int result;
	result = wifi_set_sta_power(status);
	if (result != WIFI_SUCCESS) {
		// function call to wifi_set_sta_power failed
		fprintf(stdout, "%s\n", "call to wifi_set_sta_power failed");
		fprintf(stdout, "%s\n", strerror(errno));
		fflush(stdout);
        }
        return result;
}

----
output:

call to wifi_set_sta_power failed
Permission denied

thanks,

J

[peter9477]

Have you tried to call wifi_get_status() ?

(And no, I have no idea if this works, I'm just suggesting another thing to try since the results might tell you something useful.)

[oddboy]

hey there, yes, the wifi_get_status() works.  the set power doesn't though.

[borceg]

Seems that your app is not allowed to change wifi radio power state (on/off). Docs say this:

When the device is in an operational mode other than client STA this function fails, errno is set to EBUSY, and the wifi power remains unchanged. Additional restrictions apply to power off requests if, for example, Wi-Fi is the default route for one of the perimeters, or if an application is explicitly bound to the Wi-Fi interface. In such cases the power off request fails and errno is set to EBUSY.

[peter9477]

oddboy, wifi_get_status() works you say, but what value does it return?

[oddboy]

Peter, the function returns 0, as in success.

The variable passed to the function comes back as WIFI_STATUS_RADIO_OFF (0) if the radio is off, and WIFI_STATUS_RADIO_ON (1) if the radio is on as expected. It never comes back with WIFI_STATUS_BUSY (2) - radio busy - which is what the documentation says will return if the wifi service is in a state that does not allow it to be shut off.

So wifi_get_status seems to work fine, and rather than EBUSY, I get Permission Denied.

I'm either missing something, or this function wifi_set_sta_power() is not implemented yet.

[peter9477]

There may be an undocumented permission that's required in the bar-descriptor.xml file for this to work. I seem to recall that Android apps can actually control this, so perhaps they intend to expose it, but just haven't finished up the docs and/or implementation.

[oddboy]

yeah, it must not be fully implemented.  i've tried enabling every visible permission in the bar file and still no luck.

it would be nice if the API's for controlling devices were more alike.  the Bluetooth API is pretty straight forward.  the wifi ones is a little more complicated.  i.e.with the BT device you register a callback and watch for events of interest.  with the wifi one, you just call the function and hope it works.

ah well, hopefully it gets implemented sooner or later.

[MSohm]

For reference, this is logged in Issue Tracker here:

BBTEN-538 calls to wifi_set_sta_power() fail with Permission Denied