App nRF connect for mobile (IOS) does not stop DFU when nordic BLE device reply error

[Thibaud]

Hello

I am developpping a BLE device updatable over the air with a nRF52840 chip.

Seems my device is working on battery I am not always allowing DFU. 

I am doing the ota DFU with the nRF Connect for mobile application, on IOS and when I disallowe the DFU the application does not stop trying.

It is a bit disturbing because when we use the applciation we cannot differentiate whether the update will start or not.

Best Regards

Thibaud

[Vidar Berg]

Hello,

How do you reject DFU requests in your application, do you ignore the request, or do you send a response code to the client?

Thanks,

Vidar

[Thibaud]

Hello

I decline it with mcumgr error code. I tried MGMT_ERR_EBADSTATE & MGMT_ERR_EACCESSDENIED.

Best Regards

Thibaud

[Thibaud]

Hi Vidar

In an other subject but still concerning DFU with the nRF connect for mobile app, when I do a DFU I do not get the event MGMT_EVT_OP_IMG_MGMT_DFU_STOPPED when I cancelled it and the MGMT_EVT_OP_IMG_MGMT_DFU_PENDING when the DFU is finished.

I don't know if it is because of the app or the SDK, note that I am using nRF Connect SDK v2.5.0

Best Regards

Thibaud

[Vidar Berg]

Hi Thibaud,

MGMT_ERR_EBADSTATE is not a valid return value for the 'cb_dfu_authorisation_callback'. It has to be one of the following values:

https://github.com/nrfconnect/sdk-zephyr/blob/6f5b9749499156a4ea8181aa5d32d447ecc7afc7/include/zephyr/mgmt/mcumgr/mgmt/callbacks.h#L53 

I realized this while reviewing your code.

Please try with this callback:

enum mgmt_cb_return cb_dfu_authorisation_callback(uint32_t event, enum mgmt_cb_return prev_status,
                                int32_t *rc, uint16_t *group, bool *abort_more,
                                void *data, size_t data_size)
{
	if (event == MGMT_EVT_OP_IMG_MGMT_DFU_CHUNK && !USB_STATUS)
	{
		LOG_WRN ("DFU command disallowed");
		*rc = MGMT_ERR_EBADSTATE;
		return MGMT_CB_ERROR_RC;
	}

	LOG_INF ("DFU command authorized") ;
	return MGMT_CB_OK;
}

 Best regards,

Vidar

[Thibaud]

Hi

I have the same behavior with MGMT_CB_ERROR_RC.

Best Regards

Thibaud

[Vidar Berg]

Hi Thibaud,

Are you also setting 'rc' to MGMT_ERR_EBADSTATE? This is what I observe after initiating DFU from the Device Manager app on iOS.:

Best regards,

Vidar

[Thibaud]

Hello

Thank you for your fast reaction, indeed I did not understand the utility of rc so i did not implement it, but now it is working with *rc =  MGMT_ERR_EBADSTATE

Concerning MGMT_EVT_OP_IMG_MGMT_DFU_STOPPED & MGMT_EVT_OP_IMG_MGMT_DFU_PENDING events, I see the MGMT_EVT_OP_IMG_MGMT_DFU_STOPPED when I decline the DFU but not when I canceled it by pressing cancel button on the app.

May be it could be a good improve to send the same stop event when you press cancel button than when  the DFU is stopped because of the error.

Thank you for the support

Kind regards

Thibaud

[Vidar Berg]

Hello,

I'm glad to hear that it worked. 

Thibaud said:

Concerning MGMT_EVT_OP_IMG_MGMT_DFU_STOPPED & MGMT_EVT_OP_IMG_MGMT_DFU_PENDING events, I see the MGMT_EVT_OP_IMG_MGMT_DFU_STOPPED when I decline the DFU but not when I canceled it by pressing cancel button on the app.

From what I can gather from the SMP spec, there does not appear to be any 'abort' command that can be sent after the image upload request. Ref. https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/services/device_mgmt/smp_groups/smp_group_1.html#image-upload 

But I'll ask around to see if I may have overlooked something.

Maybe you can monitor the MGMT_EVT_OP_IMG_MGMT_DFU_CHUNK event to allow the app to determine if there is any ongoing DFU operation in progress, or if it has been cancelled.

Kind regards,

Vidar

[Thibaud]

Hello

So, I am monitoring MGMT_EVT_OP_IMG_MGMT_DFU_CHUNK. The good news is, I can reach MGMT_EVT_OP_IMG_MGMT_DFU_PENDING at the end of my DFU.

Best Regards

Thibaud