Hi Francois, >>> Thanks both of you for your input. >>> >>> Here are my 100% reproducible steps: >>> - Restart bluetoothd to start fresh >>> - Remove cached device (remove 88:0F:10:9D:EB:42) >>> - Run basic scan (scan on) >>> - Wait for the device to pop up in results and stop scan (scan off) >>> - Try to connect to it (connect 88:0F:10:9D:EB:42) >>> >>> As you can read below I now have 2 "LE Connection Complete (0x01)" events. >>> >>> Bluetooth monitor ver 5.35 >>> = New Index: A4:17:31:78:A6:04 (BR/EDR,USB,hci0) >>> [hci0] 0.624321 >>> < HCI Command: LE Add Device To White List (0x08|0x0011) plen 7 >>> [hci0] 11.038826 >>> Address type: Public (0x00) >>> Address: 88:0F:10:9D:EB:42 (OUI 88-0F-10) >>>> HCI Event: Command Complete (0x0e) plen 4 [hci0] 11.040084 >>> LE Add Device To White List (0x08|0x0011) ncmd 1 >>> Status: Success (0x00) >>> < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 >>> [hci0] 11.040125 >>> Type: Passive (0x00) >>> Interval: 60.000 msec (0x0060) >>> Window: 30.000 msec (0x0030) >>> Own address type: Public (0x00) >>> Filter policy: Ignore not in white list (0x01) >>>> HCI Event: Command Complete (0x0e) plen 4 [hci0] 11.041085 >>> LE Set Scan Parameters (0x08|0x000b) ncmd 1 >>> Status: Success (0x00) >>> < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 >>> [hci0] 11.041134 >>> Scanning: Enabled (0x01) >>> Filter duplicates: Enabled (0x01) >>>> HCI Event: Command Complete (0x0e) plen 4 [hci0] 11.042084 >>> LE Set Scan Enable (0x08|0x000c) ncmd 1 >>> Status: Success (0x00) >>>> HCI Event: LE Meta Event (0x3e) plen 43 [hci0] 15.668141 >>> LE Advertising Report (0x02) >>> Num reports: 1 >>> Event type: Connectable undirected - ADV_IND (0x00) >>> Address type: Public (0x00) >>> Address: 88:0F:10:9D:EB:42 (OUI 88-0F-10) >>> Data length: 31 >>> Flags: 0x06 >>> LE General Discoverable Mode >>> BR/EDR Not Supported >>> Company: Anhui Huami Information Technology Co., Ltd. (343) >>> Data: 00f70b676930f4c909f4a5acd792a299ff02880f109deb42 >>> RSSI: -59 dBm (0xc5) >>> < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 >>> [hci0] 15.668289 >>> Scanning: Disabled (0x00) >>> Filter duplicates: Disabled (0x00) >>>> HCI Event: Command Complete (0x0e) plen 4 [hci0] 15.669062 >>> LE Set Scan Enable (0x08|0x000c) ncmd 1 >>> Status: Success (0x00) >>> < HCI Command: LE Create Connection (0x08|0x000d) plen 25 >>> [hci0] 15.669171 >>> Scan interval: 60.000 msec (0x0060) >>> Scan window: 30.000 msec (0x0030) >> >> we might should have the LE Create Connection scan with a full duty cycle here. So it does not miss any advertising PDUs. > > Is this something the Linux Bluetooth team is going to address? yes we are addressing this. Also the mgmt event with the connection failed error needs to be suppressed. While a connection attempt might still be aborted, it is not an error. It is really just lets scan one more time and try again. >>> Filter policy: White list is not used (0x00) >>> Peer address type: Public (0x00) >>> Peer address: 88:0F:10:9D:EB:42 (OUI 88-0F-10) >>> Own address type: Public (0x00) >>> Min connection interval: 50.00 msec (0x0028) >>> Max connection interval: 70.00 msec (0x0038) >>> Connection latency: 0x0000 >>> Supervision timeout: 420 msec (0x002a) >>> Min connection length: 0.000 msec (0x0000) >>> Max connection length: 0.000 msec (0x0000) >>>> HCI Event: Command Status (0x0f) plen 4 [hci0] 15.670065 >>> LE Create Connection (0x08|0x000d) ncmd 1 >>> Status: Success (0x00) >>> < HCI Command: LE Create Connection Cancel (0x08|0x000e) plen 0 >>> [hci0] 17.670566 >> >> And I think we need to increase the timeout to something like 4-5 seconds before we give up and try the next device that might have been found. >> > > For my own curiosity, how does does perform Android Bluetooth stack > when creating a LE connection? > Does it hardcode a 4-5 seconds timeout or does it use other heuristics? I honestly do not know what Android picks as default values. Easy to find out though, just enable tracing and grab the btsnoop file via adb. You can read it with btmon btw. Regards Marcel -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
