Explicit CCC added descriptor does not send notification/indication t…

[cy-kishore]

…o client

Description

Pull request type

[ x] Fix
[ ] Refactor
[ ] Target update
[ ] Functionality change
[ ] Docs update
[ ] Test update
[ ] Breaking change

Reviewers

Release Notes

[ciarmcom]

@cy-kishore, thank you for your changes.
@ARMmbed/mbed-os-pan @ARMmbed/mbed-os-maintainers please review.

[paul-szczepanek-arm]

I apologise the issue hasn't been triaged.

The lack of CCC callback is a problem that needs addressing ASAP but this needs to be fixed at the creation of the attribute at:
mbed-os\features\FEATURE_BLE\targets\TARGET_CORDIO\source\CordioGattServer.cpp

[paul-szczepanek-arm]

This is a workaround, a fix is need to solve the root cause of the problem: CCC should not have a ATTS_SET_WRITE_CBACK set in attribute settings insert_descriptor(). The special case handling of CCC should include checking for this conflict.

if (properties & WRITABLE_PROPERTIES && !(attribute_it->settings & ATTS_SET_CCC)) {
    attribute_it->settings |= ATTS_SET_WRITE_CBACK;
}

[paul-szczepanek-arm]

I really appreciate your taking the time to make the PR and I apologise for your issue not being triaged. This is a workaround rather than fix. I will make the PR for this and the other issue you reported with a proposed fix, link to it in this PR and tag you for comments to make sure it addresses your issue.

[cy-kishore]

I really appreciate your taking the time to make the PR and I apologise for your issue not being triaged. This is a workaround rather than fix. I will make the PR for this and the other issue you reported with a proposed fix, link to it in this PR and tag you for comments to make sure it addresses your issue.

Sure. Please let me know if you require any further info from me.
FYI
Initially ATTS_SET_WRITE_CBACK was not set for CCCD. But this resulted in write callback not coming to the application. we have raised the following Jira for the same and this was resolved
#9771.

After this fix we saw that Notifications and indications are not being sent. for which I have raised following Jira.
#10316

What we found is because cccCback callback is not called, the attsCccCb.pCccTbl value is not getting updated. Because of this the stack is not sending out the notification which the application is sending.

[paul-szczepanek-arm]

superseeded by #9771, please close

[cy-kishore]

superseeded by #9771, please close

Hi,
I did not understand the comment. As mentioned above in my previous comment, #9771 is raised by me and it fixes the issues of CCCD read and write callback not coming to the application. But this fix caused a side effect.

After this fix when application sends notification it is not being sent out. This PR fixes that.

What we found is, after the fix for #9771 cccCback callback is not called as it is in else if condition, the attsCccCb.pCccTbl value is not getting updated. Because of this the stack is not sending out the notification which the application is sending.

regards
Kishore

[paul-szczepanek-arm]

I pasted the wrong link in my comment above, it's superseded by #10575 - apologies for the confusion caused.

This can now be closed.

[cy-kishore]

This is fixed in #10575 . This pull request is no longer needed.