NetBSD Problem Report #13002

Received: (qmail 29967 invoked from network); 22 May 2001 01:41:37 -0000
Message-Id: <200105220138.f4M1cFs00399@zorkmid.mit.edu>
Date: Mon, 21 May 2001 21:38:15 -0400 (EDT)
From: John Hawkinson <jhawk@mit.edu>
Reply-To: jhawk@mit.edu
To: gnats-bugs@gnats.netbsd.org
Subject: ucom hangs in TIOCSETAW changing baud rate
X-Send-Pr-Version: 3.95

>Number:         13002
>Category:       kern
>Synopsis:       ucom hangs in TIOCSETAW changing baud rate
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue May 22 01:42:00 +0000 2001
>Closed-Date:    Sun May 05 04:07:51 +0000 2019
>Last-Modified:  Sun May 05 04:07:51 +0000 2019
>Originator:     John Hawkinson
>Release:        -current of 1 May 2001
>Organization:
MIT
>Environment:

System: NetBSD zorkmid.mit.edu 1.5U NetBSD 1.5U (ZORKMID-$Revision: 1.10 $) #103: Mon May 21 21:10:47 EDT 2001 jhawk@zorkmid.mit.edu:/usr/local/netbsd-current/src/sys/arch/i386/compile/ZORKMID i386


>Description:
	cu hangs when trying to connect to /dev/ttyU0, my new
USB serial adapter. It only hangs when I try to change the baud rate.
If I ^C it and try again, then it works fine at the given baud rate.

>How-To-Repeat:

zorkmid# cu -l /dev/ttyU0 -9600
^Ccu: Got interrupt signal
cu: Can't change terminal settings: Interrupted system call
^C^C^C
^C^C^Czorkmid# 
zorkmid# cu -l /dev/ttyU0 -9600
Connected.

ktrace-ing the hang, we find ourselves stuck in a TIOCSETAW:
...
   321 cu       RET   ioctl -1 errno 1 Operation not permitted
   321 cu       CALL  ioctl(0x3,TIOCSETA,0x806f054)
   321 cu       RET   ioctl 0
   321 cu       CALL  ioctl(0x3,TIOCSETAW,0x806f054)

t/t in ddb reports:

db> trace: pid 321 at 0xc6ecdcb8
bpendtsleep(c6428280,11a,c044c09a,0,0) at bpendtsleep
ttysleep(c6428238,c6428280,11a,c044c09a,0) at ttysleep+0x22
ttywait(c6428238,802c7415,ffffffff,c6428238,1fff) at ttywait+0x5f
ttioctl(c6428238,802c7415,c6ecded8,7,c6ea9c88) at ttioctl+0x5ee
ucom_do_ioctl(c086ea00,802c7415,c6ecded8,7,c6ea9c88) at ucom_do_ioctl+0x74
ucomioctl(4200,802c7415,c6ecded8,7,c6ea9c88) at ucomioctl+0x3d
spec_ioctl(c6ecddec,c6c94bd0,c6e0eac8,c6ea9c88,c044da80) at spec_ioctl+0x42
VOP_IOCTL(c6e0eac8,802c7415,c6ecded8,7,c08a0300) at VOP_IOCTL+0x46
vn_ioctl(c6c94bd0,802c7415,c6ecded8,c6ea9c88,c6ecdf88) at vn_ioctl+0xae
sys_ioctl(c6ea9c88,c6ecdf88,c6ecdf80,480fe89c,806f054) at sys_ioctl+0x31d
syscall_fancy(1f,1f,0,806f054,bfbfd434) at syscall_fancy+0xcb

I don't have a lot more time to debug this.

>Fix:
	workaround: ^C cu and try again.

>Release-Note:
>Audit-Trail:

From: John Hawkinson <jhawk@mit.edu>
To: gnats-bugs@netbsd.org
Cc:  
Subject: Re: kern/13002
Date: Tue, 22 May 2001 00:13:33 -0400 (EDT)

 Oops, I forgot to mention, this device is:

 uplcom0 at uhub0 port 2
 uplcom0: Prolific Technology Inc. PL2303 Serial adapter (ATEN/IOGEAR UC232A), rev 1.10/2.00, addr 2
 ucom0 at uplcom0

 port 2 addr 2: power 100 mA, config 1, PL2303 Serial adapter (ATEN/IOGEAR UC232A)(0x2303), Prolific Technology Inc.(0x067b), rev 2.00

 --jhawk
State-Changed-From-To: open->closed
State-Changed-By: mrg@NetBSD.org
State-Changed-When: Sun, 05 May 2019 04:07:51 +0000
State-Changed-Why:
i've successfully changed speed on uplcom(4) for a decade+.


>Unformatted:

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