Hello,
On 6.1.0-rc3, I have been seeing this error message in dmesg:
Bluetooth: hci0: HCI_REQ-0xfcf0
It is printed on every boot, resume from suspend and rfkill unblock of the Bluetooth device.
The device seems to be functioning normally though (but I have done limited testing only).
After some investigation, it turned out to be caused by
commit dd50a864ffae ("Bluetooth: Delete unreferenced hci_request code")
which modified hci_req_add() in net/bluetooth/hci_request.c to always print an error message
when that function is executed.
I have added dump_stack() to hci_req_add() and got the following backtraces:
On boot:
[ 18.487766] Bluetooth: hci0: RTL: fw version 0xab6b705c
[ 18.548951] Bluetooth: hci0: HCI_REQ-0xfcf0
[ 18.548961] CPU: 3 PID: 108 Comm: kworker/u9:0 Not tainted 6.1.0-rc3unif4-00001-gb33a0948e932 #86
[ 18.548965] Hardware name: HP HP Laptop 17-by0xxx/84CA, BIOS F.66 03/29/2022
[ 18.548968] Workqueue: hci0 hci_power_on [bluetooth]
[ 18.549018] Call Trace:
[ 18.549020] <TASK>
[ 18.549022] dump_stack_lvl+0x38/0x4d
[ 18.549030] dump_stack+0x10/0x16
[ 18.549035] hci_req_add+0x47/0x70 [bluetooth]
[ 18.549093] msft_set_filter_enable+0x59/0x90 [bluetooth]
[ 18.549147] msft_do_open+0x131/0x220 [bluetooth]
[ 18.549198] hci_dev_open_sync+0x646/0xc20 [bluetooth]
[ 18.549249] hci_dev_do_open+0x2a/0x60 [bluetooth]
[ 18.549282] hci_power_on+0x53/0x210 [bluetooth]
[ 18.549317] process_one_work+0x21f/0x3f0
[ 18.549323] worker_thread+0x4a/0x3c0
[ 18.549328] ? process_one_work+0x3f0/0x3f0
[ 18.549332] kthread+0xff/0x130
[ 18.549336] ? kthread_complete_and_exit+0x20/0x20
[ 18.549340] ret_from_fork+0x22/0x30
[ 18.549347] </TASK>
[ 21.165060] EXT4-fs (dm-7): mounted filesystem with ordered data mode. Quota mode: none.
on rfkill unblock:
[ 1671.040970] Bluetooth: hci0: HCI_REQ-0xfcf0
[ 1671.040992] CPU: 3 PID: 5006 Comm: kworker/u9:2 Not tainted 6.1.0-rc3unif4-00001-gb33a0948e932 #86
[ 1671.041005] Hardware name: HP HP Laptop 17-by0xxx/84CA, BIOS F.66 03/29/2022
[ 1671.041012] Workqueue: hci0 hci_cmd_sync_work [bluetooth]
[ 1671.041194] Call Trace:
[ 1671.041200] <TASK>
[ 1671.041208] dump_stack_lvl+0x38/0x4d
[ 1671.041227] dump_stack+0x10/0x16
[ 1671.041241] hci_req_add+0x47/0x70 [bluetooth]
[ 1671.041408] msft_set_filter_enable+0x59/0x90 [bluetooth]
[ 1671.041579] msft_do_open+0x131/0x220 [bluetooth]
[ 1671.041683] hci_dev_open_sync+0x646/0xc20 [bluetooth]
[ 1671.041787] hci_set_powered_sync+0xd4/0x240 [bluetooth]
[ 1671.041887] set_powered_sync+0x20/0x60 [bluetooth]
[ 1671.041975] hci_cmd_sync_work+0xa8/0x150 [bluetooth]
[ 1671.042079] process_one_work+0x21f/0x3f0
[ 1671.042092] worker_thread+0x4a/0x3c0
[ 1671.042102] ? process_one_work+0x3f0/0x3f0
[ 1671.042111] kthread+0xff/0x130
[ 1671.042119] ? kthread_complete_and_exit+0x20/0x20
[ 1671.042128] ret_from_fork+0x22/0x30
[ 1671.042142] </TASK>
My hardware: HP laptop 17-by0001nw, device is a Realtek combo card:
"Realtek RTL8822BE 802.11 ac 2×2 WiFi + Bluetooth 4.2 Combo Adapter (MU-MIMO supported)"
I am ready to provide additional information and testing, if need be.
Greetings,
Mateusz Jończyk
