kernel freeze related to rfcomm and maybe tty

Kernel freezes for ~2 seconds after trying to access /dev/rfcommX device.
Steps to reproduce:
1. Edit /etc/bluetooth/rfcomm.conf - uncomment default config, set "bind" to "yes".
2. Issue "sudo rfcomm bind all" to create /dev/rfcomm0 device node.
3. Issue "cat /dev/rfcomm0" to trigger a bug.
Everything freezes (at least GUI): cursor does not move, no response from keypresses, no gui redraw for 2~3 seconds.
Then cat displays expected error message "cat: /dev/rfcomm0: Host is down" and system starts to respond again.
What expected (and occurs with 2.6.35) : no freeze between cat and error message.
Things goes worse when device, mentioned in /etc/bluetooth/rfcomm.conf is in range and not paired - system displays pairing request and locks up for a longer time, maybe completely - I did not wait longer than ~30 seconds and turned off bluetooth device.
Bug may be introduced with recent changes to tty code to remove dependency on BKL. 2.6.36-rc1 shows this bug.
Will try development kernel with recent tty fixes and investigate further.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-1-generic 2.6.38-1.28
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.38-1.28-generic 2.6.38-rc2
Uname: Linux 2.6.38-1-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC272 Analog [ALC272 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC272 Analog [ALC272 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: vlad 10147 F.... pulseaudio
CRDA: Error: [Errno 2] Нет такого файла или каталога
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf0340000 irq 43'
   Mixer name : 'Realtek ALC272'
   Components : 'HDA:10ec0272,144dca00,00100001'
   Controls : 19
   Simple ctrls : 11
Date: Sun Feb 6 01:25:29 2011
HibernationDevice: RESUME=UUID=bfb94be8-7bdf-433b-8efa-340064d00a36
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110202)
MachineType: SAMSUNG ELECTRONICS CO., LTD. NC10
ProcEnviron:
 LANGUAGE=ru_RU.UTF-8:ru:en_GB:en
 LANG=ru_RU.UTF-8
 LC_MESSAGES=ru_RU.utf8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-1-generic root=UUID=d9cd70a9-5da9-47e7-8087-f9d08e9d7a10 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-1-generic N/A
 linux-backports-modules-2.6.38-1-generic N/A
 linux-firmware 1.46
SourcePackage: linux
dmi.bios.date: 09/08/2009
dmi.bios.vendor: Phoenix Technologies Ltd.
dmi.bios.version: 11CA.M015.20090908.RHU
dmi.board.name: NC10
dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnPhoenixTechnologiesLtd.:bvr11CA.M015.20090908.RHU:bd09/08/2009:svnSAMSUNGELECTRONICSCO.,LTD.:pnNC10:pvrNotApplicable:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNC10:rvrNotApplicable:cvnSAMSUNGELECTRONICSCO.,LTD.:ct10:cvrN/A:
dmi.product.name: NC10
dmi.product.version: Not Applicable
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.