[mythtv-users] kernel NULL pointer

[Paul Andreassen]

Hi,

I'm having trouble with mythtv when I try to play videos.  Mythtv hangs
with this in the /var/log/syslog:

Unable to handle kernel NULL pointer dereference at virtual address
00000004
 printing eip:
c01150f3
*pde = 00000000
Oops: 0002 [#1]
PREEMPT 
Modules linked in: ipv6 af_packet snd_via82xx snd_ac97_codec snd_pcm_oss
snd_mixer_oss snd_pcm snd_timer snd_page_alloc snd_mpu401_uart
snd_rawmidi snd_seq_device snd ehci_hcd usbhid eth1394 uhci_hcd usbcore
ohci1394 ieee1394 dst dvb_bt8xx dvb_core bt878 tuner bttv video_buf
i2c_algo_bit v4l2_common btcx_risc soundcore hw_random longhaul
freq_table vt1211 i2c_sensor i2c_core via videodev via_agp agpgart
via_rhine mii crc32 unix
CPU:    0
EIP:    0060:[add_wait_queue+24/59]    Not tainted VLI
EFLAGS: 00210002   (2.6.9-epiamn) 
EIP is at add_wait_queue+0x18/0x3b
eax: de9c60d8   ebx: cdefff20   ecx: cdefe000   edx: cdefff14
esi: 00000000   edi: 00200246   ebp: 00000000   esp: cdeffed8
ds: 007b   es: 007b   ss: 0068
Process mythfrontend (pid: 3320, threadinfo=cdefe000 task=ce322020)
Stack: de9c5ec0 cdefff08 cdefff28 de9b6141 0005fdf8 cdefff58 de9ba283
00000000 
       ce322020 c0114443 00000000 00000000 00000001 de9bcd09 00000000
00000000 
       ce322020 c0114443 00000000 00000000 c014b0ea cdefff54 b130ca24
de9c5ec0 
Call Trace:
 [pg0+509854017/1070089216] via_driver_vblank_wait+0xc1/0x13c [via]
 [pg0+509870723/1070089216] viadrv_open+0x66/0xba [via]
 [default_wake_function+0/12] default_wake_function+0x0/0xc
 [pg0+509881609/1070089216] viadrv_stub_open+0xa0/0x175 [via]
 [default_wake_function+0/12] default_wake_function+0x0/0xc
 [chrdev_open+373/442] chrdev_open+0x175/0x1ba
 [pg0+509867777/1070089216] viadrv_wait_vblank+0x1bc/0x1ff [via]
 [note_interrupt+60/102] note_interrupt+0x3c/0x66
 [pg0+509872158/1070089216] viadrv_ioctl+0xe3/0xef [via]
 [pg0+509867333/1070089216] viadrv_wait_vblank+0x0/0x1ff [via]
 [note_interrupt+60/102] note_interrupt+0x3c/0x66
 [sys_ioctl+498/571] sys_ioctl+0x1f2/0x23b
 [syscall_call+7/11] syscall_call+0x7/0xb
 [note_interrupt+60/102] note_interrupt+0x3c/0x66
Code: 8b 83 90 01 00 00 e8 a2 d1 00 00 89 d8 5b e9 37 ff ff ff 57 56 53
83 22 fe 9c 5f fa b9 00 e0 ff ff 21 e1 ff 41 14 8b 30 8d 5a 0c <89> 5e
04 89 72 0c 89 43 04 89 18 57 9d ff 49 14 8b 41 08 a8 08 
 <6>note: mythfrontend[3320] exited with preempt_count 2

This seems to indicate a problem with the via_driver.

I'm using Debian / Sid with:

mythtv 0.16 from 
http://dijkstra.csh.rit.edu/~mdz/debian/dists/unstable/mythtv/
I've recompiled it twice.  Doesn't matter if libddmpeg is enabled or
not.  Doesn't matter if opengl_vsync is enabled or not.

mythtv 0.15 did play video.  (can't test because no longer have)

linux-2.6.7-epia1 with drm 1.3.0 and via_v4l_drv

linux-2.6.9-epia with drm 2.0.0 and no via_v4l_drv

xserver-common 4.3.0.dfsg.1-8

opensource_040701.tgz from http://unichrome.sourceforge.net/

mplayer will play video.

Willing to jump through hoops to get this to work. ;-)

Paul