BLE GATT descriptor set to DESCRIPTOR_READ (0x01) returns Error Code: Read Not Permitted (0x02)
Port, board and/or hardware
esp32
MicroPython version
This issue started showing from MicroPython v1.20 onwards.
V1.23 is confirmed to still have the issue.
V1.19 is confirmed to NOT have the issue.
Reproduction
I'm using my MicroPythonBLEHID library.
On line 588, among others, I define the following HID service description:
self.HIDS = (
UUID(0x1812),
(
(UUID(0x2A4A), F_READ),
(UUID(0x2A4B), F_READ),
(UUID(0x2A4C), F_WRITE),
(UUID(0x2A4D), F_READ_NOTIFY, ((UUID(0x2908), DESCRIPTOR_READ),)),
(UUID(0x2A4E), F_READ_WRITE),
),
)
Where DESCRIPTOR_READ = 0x01, as specified here.
Expected behaviour
No issues.
Observed behaviour
The value 0x01 of the report reference UUID(0x2908) returns a Rcvd Error Response - Read Not Permitted, Handle: 0x0030 (Human Interface Device: Report: Report Reference) message when intercepted with Pcap/Wireshark, causing a driver failure.
Additional Information
When I set the descriptor to 0x02, the issue is resolved. However, this is the write flag, and not read, and therefore wrong. My current version of the library uses this value to 'make it work', but this is incorrect.
Note that the issue persists even when always returning _GATTS_NO_ERROR (0x00) with every _IRQ_GATTS_READ_REQUEST.
Code of Conduct
Yes, I agree
Pico-W OSError: [Errno 114] EALREADY
MicroPython v1.22.1 on 2024-01-05; Raspberry Pi Pico W with RP2040
This error occurs as part of a BLE central implementation. I'm using the BLE class direct rather than the aioble library.
Following scanning and a successful _IRQ_PERIPHERAL_CONNECT event, service discovery is initiated. During service discovery the attribute tree is navigated recording service handles, characteristic handles and descriptor handles. This includes recording handles for the CCC descriptor for characteristics with Notify enabled (UUID = 0x2902). Following service discovery MTUs are exchanged. The CCC descriptors then have 1 written to them, to enable notifications to be reported by the server. The first of these generates an _IRQ_GATTC_WRITE_DONE with a result of 0 (OK). The second write causes the OSError 114.
This failure is specific to the Pico-W with the Infineon radio. The code works as expected without the OSError on both an ESP32 and an Arduino Nano RP2040 Connect (Nina W102 uBlox radio). I've also tried it with two different peripheral implementations - micropython on the RP2040 Connect and c++/ARM mbed Bluetooth library on an Arduino Nano BLE. The failure happens consistently with both peripheral implementations.