Created attachment 284815 [details]
lspci -vvnn

Created attachment 285745 [details]
Output of lsusb (wifi/bluetooth chip is connected via usb on T490)

I'm experiencing the same problem. I'm also unable to reconnect to bluetooth devices after the pairing and the initial connect succeeded.

I have the same issue

Device was discovered and connected fine the first time, then it was disconnected immediately.

Every time I try to connect it again, it disconnects.

s@OrangeDemon:~$ sudo hciconfig hci0 -a
hci0:	Type: Primary  Bus: USB
	BD Address: DC:FB:48:28:FA:95  ACL MTU: 1021:4  SCO MTU: 96:6
	UP RUNNING PSCAN ISCAN 
	RX bytes:76148 acl:16 sco:0 events:2184 errors:0
	TX bytes:13222 acl:14 sco:0 commands:589 errors:0
	Features: 0xbf 0xfe 0x0f 0xfe 0xdb 0xff 0x7b 0x87
	Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 
	Link policy: RSWITCH SNIFF 
	Link mode: SLAVE ACCEPT 
	Name: 'OrangeDemon'
	Class: 0x100104
	Service Classes: Object Transfer
	Device Class: Computer, Desktop workstation
	HCI Version: 5.0 (0x9)  Revision: 0x100
	LMP Version: 5.0 (0x9)  Subversion: 0x100
	Manufacturer: Intel Corp. (2)

dmesg:
[    4.172065] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[    4.172066] Bluetooth: BNEP filters: protocol multicast
[    4.172068] Bluetooth: BNEP socket layer initialized
..
[   13.392448] Bluetooth: RFCOMM TTY layer initialized
[   13.392452] Bluetooth: RFCOMM socket layer initialized
[   13.392456] Bluetooth: RFCOMM ver 1.11
[  246.531147] debugfs: File 'le_min_key_size' in directory 'hci0' already present!
[  246.531153] debugfs: File 'le_max_key_size' in directory 'hci0' already present!
[  275.658457] debugfs: File 'le_min_key_size' in directory 'hci0' already present!
[  275.658463] debugfs: File 'le_max_key_size' in directory 'hci0' already present!

Logged debugfs error and not being able to connect should not have any relation.

I would suggest opening separate ticket for connection problem. Also please use btmon to capture the problem.

(In reply to Matias Karhumaa from comment #4)
> Logged debugfs error and not being able to connect should not have any
> relation.
> 
> I would suggest opening separate ticket for connection problem. Also please
> use btmon to capture the problem.

You are totally right Matias, this was not related, I was able to connect my headset without any problem.....

This bug occurs after a software suspend/resume cycle. It's valid and it needs to be fixed. Some logic in the driver doesn't handle suspend properly.

The bug is reproducible in kernel 5.5.15.

Hi Artem,

This has been fixed in 5.6 kernel: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/bluetooth/smp.c?id=18f81241b74fb49d576c83fbbab9a0b6e3bb20d4

Best regards,
Matias

Still seeing this error with kernel 5.6.14 and the most recent firmware:

dmesg:
[  271.857043] debugfs: File 'force_bredr_smp' in directory 'hci0' already present!

Seems like the patch fixed two of the debugfs calls but not the third one.

I am suddenly seeing the same error after suspend/hibernation on my laptop with my Microsoft Surface bluetooth mouse, using latest Ubuntu kernel 5.4.0-47-generic #51-Ubuntu SMP Fri Sep 4 19:50:52 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux:


[82250.719088] Bluetooth: hci0: Bootloader revision 0.0 build 26 week 38 2015
[82250.720091] Bluetooth: hci0: Device revision is 16
[82250.720092] Bluetooth: hci0: Secure boot is enabled
[82250.720093] Bluetooth: hci0: OTP lock is enabled
[82250.720094] Bluetooth: hci0: API lock is enabled
[82250.720094] Bluetooth: hci0: Debug lock is disabled
[82250.720095] Bluetooth: hci0: Minimum firmware build 1 week 10 2014
[82250.720099] Bluetooth: hci0: Found device firmware: intel/ibt-12-16.sfi
[82250.722178] done.
[82250.757394] PM: suspend exit
[82250.980766] Generic FE-GE Realtek PHY r8169-200:00: attached PHY driver [Generic FE-GE Realtek PHY] (mii_bus:phy_addr=r8169-200:00, irq=IGNORE)
[82251.091652] r8169 0000:02:00.0 enp2s0: Link is Down
[82252.225425] Bluetooth: hci0: Waiting for firmware download to complete
[82252.226105] Bluetooth: hci0: Firmware loaded in 1472555 usecs
[82252.226211] Bluetooth: hci0: Waiting for device to boot
[82252.238154] Bluetooth: hci0: Device booted in 11754 usecs
[82252.238165] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-12-16.ddc
[82252.241173] Bluetooth: hci0: Applying Intel DDC parameters completed
[82326.333382] Lockdown: systemd-logind: hibernation is restricted; see man kernel_lockdown.7
[82358.148284] debugfs: File 'le_min_key_size' in directory 'hci0' already present!
[82358.148303] debugfs: File 'le_max_key_size' in directory 'hci0' already present!

Of course you are seeing that error if you use 5.4 and the fix landed in 5.6 with no backports?

If any the true shame is that nobody has yet addressed the same problem with "force_bredr_smp"

https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git/commit/?id=82493316507a720b6faa2ec23971c0ca89c6dcb0 ("Bluetooth: Move force_bredr_smp debugfs into hci_debugfs_create_bredr")

Guess we'll have to wait 5.11 if any kind of backporting is unthinkable.

Hi all. I don't see why only 5.11 fixes this. As for me I see such an issue after BT was off and there was the sleep of laptop. 

debugfs: File 'force_bredr_smp' in directory 'hci0' already present!

uname -a
Linux ice-ubuntu 5.8.0-34-generic #37-Ubuntu SMP Thu Dec 10 18:01:14 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux