nrf_gzll_enable stuck nrf_impala.c 442

[astella]

To the kind attention of Nordic support team,

I need to disable, enable gzll more times. When enabling it, code gets often stuck in my case as in figure: nrf_impala.c 442. What could be?

Is it possible for you to say what could be the cause, having access at gzll source code? Thank you for your kindness 

[Håkon Alseth]

Hi,

 

It looks like it is stuck trying to start up the HFCLK.

Is this consistent behavior on your end? Could you try stopping the HFCLK before re-starting gazell, just to see if the behavior changes then?

 

Kind regards,

Håkon

[astella]

Hi, thank you very much for replying us. Sorry, I have a doubt, are we talking about HFCLK or LFCLK? I'm asking because in your sdk16 multiprotocol ble_app_gzll you are using: 

// Request Low frequency clock to re-enable the clock after the softdevice stops it.
nrf_drv_clock_lfclk_request(NULL);

err_code = bsp_indication_set(BSP_INDICATE_IDLE);
APP_ERROR_CHECK(err_code);

// Enable Gazell.
gzll_app_start();

 .. And then

nrf_drv_clock_lfclk_release();

// Disable Gazell.
gzll_app_stop();

err_code = bsp_indication_set(BSP_INDICATE_IDLE);
APP_ERROR_CHECK(err_code);

// Re-enable the softdevice stack.
ble_stack_start();
ble_hrs_app_start();

I'm also using in this case a Raytac module, nRF52833 based, and modified sdk_config.h so to have RC as a base for LFCLK. It seems also lfclk_stop is failing sometime, and as you point out this could be related to the issue in re-starting gzll. Also this prevents to re-enable softdevice as sd_softdevice_enable gets stuck as well. In the following pictures there is the situation before calling sd_softdevice_enable, and when it is not working LFCLKSTAT is different. I'll try to see what are the differences in the project I modified with respect to your multiprotocol example. If you have any suggestions, will be more than welcome. Thank you for your work

[Håkon Alseth]

Hi,

 

It looks like its stuck trying to start the HFCLK (not the LFCLK), based on where its stuck in nrf_gzll.

Do you have any issues using the device, ie: communicating to it over bluetooth / gzll? If there's problems with the external crystal, the softdevice will run on HFINT (very imprecise) and you will not be able to use the radio properly.

 

Kind regards,

Håkon