Hi Konstantin, > It seems that there's a bug in Bluetooth stack of 4.20 kernel. I > discovered it during Bluetooth qualification tests. L2CAP/COS/CFD/BV- > 12-C [Unknown Option Response] test fails because instead of > "Configuration Response" with error code 0x0003 "unknown option" the > Bluetooth stack generates "Command Reject". > > I think, this happens because the tester (Bluetooth SIG PTS) uses hints > as unknown options, and the Bluetooth stack has special handling for > hints. > > I made a small patch in order to overcome this problem. Please confirm, > that the patch is feasible. If not, please suggest how to fix the > "Command Reject" problem. is the limited to 4.20 kernel or does it also happen with the latest 5.5 kernel? Regards Marcel