Re: kern/49831: kernel panic on close of ucom tty

[Iain Hibbert <plunky%ogmig.net@localhost>]

On Wed, 29 Jun 2016, Nick Hudson wrote:

> http://www.netbsd.org/~skrll/nhusb.amd64.3.netbsd
> 
> is ready for you to try

Hi

(I found it, was not in public directory :-)

with this one, some progress

NetBSD 7.99.29 (GENERIC) #26: Wed Jun 29 07:53:42 BST 2016
	nick@zoom:/wrk/nhusb/obj.amd64/wrk/nhusb/src/sys/arch/amd64/compile/GENERIC
[...]
ehci0: handing over full speed device on port 3 to uhci1
umct0 at uhub1 port 1
umct0: Targus Group Intl Targus Group Intl, rev 1.10/1.03, addr 2
ucom0 at umct0

at this point the device attaches and detaches ok. With nothing connected 
to the remote end I can open the device 'cu -l /dev/ttyU0' and disconnect 
just fine; I did this several times with no error

Then I connected a device to the RS232 port, and connected again.. it 
opened fine, but as soon as I tried to send data I got a panic assertion

panic: kernel debugging assertion "cp == ub->ub_data" failed: file "/wrk/nhusb/src/sys/dev/usb/ucom.c", line 1485 
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff80114c15 cs 8 rflags 246 cr2 7e86e2d5ee10 ilevel 5 rsp fffffe8040013d90
curlwp 0xfffffe813bb2b440 pid 0.6 lowest kstack 0xfffffe80400102c0
Stopped in pid 0.6 (system) at	netbsd:breakpoint+0x5:	leave	
db{0}>
breakpoint() at netbsd:breakpoint+0x5
vpanic() at netbsd:vpanic+0x140
cd_play_msf() at netbsd:cd_play_msf
ucomreadcb() at netbsd:ucomreadcb+0x3fc
usb_transfer_complete() at netbsd:usb_transfer_complete+0x39f
uhci_softintr() at netbsd:uhci_softintr+0x14d
usb_soft_intr() at netbsd:usb_soft_intr+0x1f
softint_dispatch() at netbsd:softint_dispatch+0xd3
DDB lost frame for netbsd:Xsoftintr+0x4f, trying 0xfffffe8040013ff0
Xsoftintr() at netbsd:Xsoftintr+0x4f
--- interrupt ---
0:
db{0}>

thanks
iain