kern/42838: sys/dev/usb/ucom.c 1.82 broke utfdi(4)

[tnn%NetBSD.org@localhost]

>Number:         42838
>Category:       kern
>Synopsis:       sys/dev/usb/ucom.c 1.82 broke utfdi(4)
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Feb 17 20:45:00 +0000 2010
>Originator:     Tobias Nygren
>Release:        5.99.24 i386
>Organization:
>Environment:
>Description:
Opening the uftdi(4) com port with tip(1) wedges the tip process (probably at 
spltty()) and the kernel stops responding:

ehci0: handing over full speed device on port 1 to uhci0
uftdi0 at uhub0 port 1
uftdi0: FTDI FT232R USB UART, rev 2.00/6.00, addr 2
ucom0 at uftdi0 portno 1

uftdi_param: sc=0xcccd6cbc
uftdi_status: msr=0x00 lsr=0x00
uftdi_param: sc=0xcccd6cbc
uftdi_set: sc=0xcccd6cbc, port=1 reg=1 onoff=1
uftdi_set: sc=0xcccd6cbc, port=1 reg=2 onoff=1
uftdi_param: sc=0xcccd6cbc

db{0}> trace: pid 41 lid 1 at 0xcd6ba76c
sleepq_block(0,0,c0a70150,0,0,c2986600,cd6ba7cc,c06f1185,c29d133c,0) at 
netbsd:sleepq_block+0x182
usbd_transfer(c29d1300,c2986600,0,1388,cd6ba8a4,0,0,0,0,cd5d0540) at 
netbsd:usbd_transfer+0x1cb
usbd_do_request_flags_pipe(c2986600,c2986500,cd6ba8a4,0,0,0,1388,c063dcb3,c0a67baa,5)
 at netbsd:usbd_do_request_flags_pipe+0xd5
usbd_do_request_flags(c2986600,cd6ba8a4,0,0,0,1388,cd6ba8bc,c06b8b05,c2986600,cd6ba8a4)
 at netbsd:usbd_do_request_flags+0x3c
usbd_do_request(c2986600,cd6ba8a4,0,c0637c2c,cbc89c10,c0b87b58,1a8bc,cccd2c10,41380340,1)
 at netbsd:usbd_do_request+0x37
uftdi_param(cccd6cbc,1,cd6bac50,cccd2c10,cd6bac50,cccd2c10,cd6baa5c,c0684575,cccd2c10,cd6bac50)
 at netbsd:uftdi_param+0xfd
ucomparam(cccd2c10,cd6bac50,0,10,cd5d0540,ccd14d14,0,cccd2c10,ccd14d14,cd5d0540)
 at netbsd:ucomparam+0xbc
ttioctl(cccd2c10,802c7416,cd6bac50,4007,cd5d0540,cd2f2684,0,cbeac520,0,cd5d0540)
 at netbsd:ttioctl+0x635
ucomioctl(4200,0,802c7416,cd6bac50,4007,cd5d0540,cd2f2684,cd5d0540,4007,cd6bac50)
 at netbsd:ucomioctl+0xe0
cdev_ioctl(4200,0,802c7416,cd6bac50,4007,cd5d0540,4200,0,cd2f2684,802c7416) at 
netbsd:cdev_ioctl+0x75
spec_ioctl(cd6bab30,0,cd6bab3c,c079cc15,cbf29c50,cd6432c0,cd6bab4c,c09d23a0,cd2f2684,802c7416)
 at netbsd:spec_ioctl+0xa6
VOP_IOCTL(cd2f2684,802c7416,cd6bac50,4007,cd5cfc00,cd5d0540,0,0,0,0) at 
netbsd:VOP_IOCTL+0x74
vn_ioctl(cccf6640,802c7416,cd6bac50,cd643140,cd643240,ffffffff,0,ffffffed,2,802c)
 at netbsd:vn_ioctl+0x5d
sys_ioctl(cd5d0540,cd6bad00,cd6bad28,bbbe1074,bbbe1000,cd66db30,36,3,802c7416,bfbfed94)
 at netbsd:sys_ioctl+0xf3
syscall(cd6bad48,b3,ab,1f,1f,bbbe44c0,3,bfbfed78,bbbd66a4,bfbfed94) at 
netbsd:syscall+0xc4

>How-To-Repeat:
attach to the com port with tip(1).
>Fix:
Back out sys/dev/usb/ucom.c 1.82