Rebooting problems with /dev/cxm0

[Erin E Conn]

I was able to get my PVR250 working using the pvr250 driver from ports, 
although I had to do a little tweaking in cxm_eeprom.c to get it to 
ignore my "unsupported" tuner. I was able to set the input to svideo 
using pvr250-setchannel and cat /dev/cxm0 to an mpeg file (briefly). 
However, if I try to cat /dev/cxm0 or mplayer /dev/cxm0 (or basically 
anything that reads data from this device) for anywhere from 2-5 
minutes, my entire system stops responding to input and reboots after 
about 30 seconds.

Before I tried completely removing and reinstalling the port, along with 
rebuilding my kernel, I was getting a lot of "encoder dma not enough 
buffer space free" messages, but now after rebuilding the kernel and 
reinstalling the port there is no indication in /var/log messages of 
what caused the reboot:
Apr 18 20:01:46 chimera kernel: cxm_iic0: <Conexant iTVC15 / iTVC16 I2C 
controll
er> on cxm0
Apr 18 20:01:46 chimera kernel: iicbb0: <I2C bit-banging driver> on cxm_iic0
Apr 18 20:01:46 chimera kernel: iicbus0: <Philips I2C bus> on iicbb0 
master-only
Apr 18 20:01:46 chimera kernel: cxm0: TCL 2002N-6A tuner
Apr 18 20:01:46 chimera kernel: cxm0: SAA7115 rev 1 video decoder
Apr 18 20:01:46 chimera kernel: cxm0: MSP3445G-B8 audio decoder
Apr 18 20:01:46 chimera kernel: cxm0: IR Remote
Apr 18 20:01:46 chimera kernel: cxm0: [GIANT-LOCKED]
Apr 18 20:01:46 chimera kernel: cxm0: encoder firmware version 0x2050032
Apr 18 20:02:08 chimera kernel: cxm0: video decoder failed to lock
Apr 18 20:09:47 chimera syslogd: kernel boot file is /boot/kernel/kernel
Apr 18 20:09:47 chimera kernel: Copyright (c) 1992-2006 The FreeBSD Project.
Apr 18 20:09:47 chimera kernel: Copyright (c) 1979, 1980, 1983, 1986, 
1988, 1989
, 1991, 1992, 1993, 1994
Apr 18 20:09:47 chimera kernel: The Regents of the University of 
California. All
  rights reserved.
Apr 18 20:09:47 chimera kernel: FreeBSD 6.1-PRERELEASE #0: Sat Apr  8 
16:31:53 E
DT 2006
Apr 18 20:09:47 chimera kernel: 
root at chimera.homeunix.org:/usr/obj/usr/src/sys/T
UNER

I do not think it is a resource issue, as the device works fine in 
Windows using the provided WinTV software. Has anyone else experienced 
similar issues with this card or any suggestions for remedying this problem?

[erin at chimera] ~> uname -imprs
FreeBSD 6.1-PRERELEASE i386 i386 GENERIC

Hardware
========
CPU: AMD Duron 1300MHz
RAM: 384 MB SDRAM
GPU: nVidia GeForce 4 TI 4800
Video RAM: 128MB
Capture card: Hauppage PVR-250 Model #: 980