Question about "Queued Writes module"

[Vyacheslav Lebets]

Hi.

I want to ask Nordic employees about the Queued Writes module.
Tell me please, is this module required for all applications?
If it is not required, then why in all examples it is initialized even when NRF_BLE_QWR_MAX_ATTR = 0?
After all, when NRF_BLE_QWR_MAX_ATTR = 0, the module simply does not work. Then why do you initialize it in all the examples?
It is logical to assume that the module is needed even if it is not initialized?

Thanks.

[Einar Thorsrud]

Hi,

Yes, the module is needed even if it is not initialized. All BLE examples started using the Queued write module in SDK 15.0.0. In earlier SDK examples the peer could cause and assert by issuing long writes which was not handled by the application. Using the queued write module with NRF_BLE_QWR_MAX_ATTR = 0 fixes this issue.

From SDK 15.0.0 release notes:

BLE examples changed to use the Queued Write module (nrf_ble_qwr). Applications must explicitly configure characteristics to accept long writes. See app_ble_qwr for an example of this. This fixes a problem where peers could cause our devices to assert by issuing long writes.

[Vyacheslav Lebets]

Thanks, Einar !!!
The question was asked for a reason.
When switching to SDK 15 from 12.3, we encountered some problems in GATT. 
I hope that using this module will solve the problems.

Thanks for answer! 

Best regards, Vyacheslav.