Hi Vasily, >>> Some adapters (e.g. RTL8723CS) advertise that they have more than >>> 2 pages for local ext features, but they don't support any features >>> declared in these pages. RTL8723CS reports max_page = 2 and declares >>> support for sync train and secure connection, but it responds with >>> either garbage or with error in status on corresponding commands. >> >> please send the btmon for this so I can see what the controller is responding. > > Here is relevant part: > > < HCI Command: Read Local Extend.. (0x04|0x0004) plen 1 #228 [hci0] 6.889869 > Page: 2 >> HCI Event: Command Complete (0x0e) plen 14 #229 [hci0] 6.890487 > Read Local Extended Features (0x04|0x0004) ncmd 2 > Status: Success (0x00) > Page: 2/2 > Features: 0x5f 0x03 0x00 0x00 0x00 0x00 0x00 0x00 > Connectionless Slave Broadcast - Master > Connectionless Slave Broadcast - Slave > Synchronization Train > Synchronization Scan > Inquiry Response Notification Event > Coarse Clock Adjustment > Secure Connections (Controller Support) > Ping > < HCI Command: Delete Stored Lin.. (0x03|0x0012) plen 7 #230 [hci0] 6.890559 > Address: 00:00:00:00:00:00 (OUI 00-00-00) > Delete all: 0x01 >> HCI Event: Command Complete (0x0e) plen 6 #231 [hci0] 6.891170 > Delete Stored Link Key (0x03|0x0012) ncmd 2 > Status: Success (0x00) > Num keys: 0 > < HCI Command: Read Synchronizat.. (0x03|0x0077) plen 0 #232 [hci0] 6.891199 >> HCI Event: Command Complete (0x0e) plen 9 #233 [hci0] 6.891788 > Read Synchronization Train Parameters (0x03|0x0077) ncmd 2 > invalid packet size > 01 ac bd 11 80 80 ...... > = Close Index: 00:E0:4C:23:99:87 [hci0] 6.891832 > > hci0 registration stops here and bluetoothctl doesn't even see the controller. maybe just the read sync train params command is broken? Can you change the init code and not send it and see if the rest of the init phase proceeds. I would rather have the secure connections actually tested before dismissing it altogether. Mind you, there were broken Broadcom implementation of connectionless slave broadcast as well. Maybe this is similar. Regards Marcel