pvrusb kernel oops in Mythbuntu Lucid

[Michal Witkowski]

After upgrading my Mythbuntu setup (WinTV PVR USB2) from 9.10 to 10.04 LTS, I get kernel oopses related to the pvrusb2 module when resuming/suspending/unloading it.

Steps to reproduce:
1. Load system with the pvrusb2 module loaded (no modprobe.conf settings)
2. pvrusb2 is usable, I can watch TV
3. Try to unload the moduel using modprobe -r pvrusb2
Observable consequences:
1. modprobe -r pvrusb2 hangs
2. dmesg shows a kernel oops (appended)
3. You can't remove the module. A cold reboot is required.

Before (in 9.10) I had no problems with unloading/suspending the pvrusb2 module. Please disregard the tainted information in the call trace, as I'm using proprietary nvidia drivers.

It is highly likely that the bug is caused by relatively harmless change in pvrusb2 related to printing messages, which was introduced in kernel 2.6.32. I checked the pvrusb2 mailing list and found a thread which describes an identical problem to mine with an explaination from a pvrusb2 developer:
http://www.isely.net/pipermail/pvrusb2/2010-April/002835.html

Dmesg of the kernel oops:
[ 180.972026] usbcore: deregistering interface driver pvrusb2
[ 180.972083] pvrusb2: Device being rendered inoperable
[ 180.972264] pvrusb2: unregistered device video0 [mpeg]
[ 180.972345] pvrusb2: unregistered device radio0 [mpeg]
[ 180.974077] tuner-simple 1-0061: destroying instance
[ 180.974198] tda9887 1-0043: destroying instance
[ 180.974332] BUG: unable to handle kernel paging request at 00100100
[ 180.974343] IP: [<00100100>] 0x100100
[ 180.974359] *pde = 6e557067
[ 180.974366] Oops: 0000 [#1] SMP
[ 180.974372] last sysfs file: /sys/module/pvrusb2/refcnt
[ 180.974379] Modules linked in: vboxnetadp vboxnetflt vboxdrv lirc_serial nfs lockd nfs_acl lirc_dev auth_rpcgss i2c_algo_bit sunrpc tuner_simple tuner_types snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm tda9887 snd_seq_dummy snd_seq_oss snd_seq_midi tda8290 snd_rawmidi snd_seq_midi_event fbcon wm8775 snd_seq tileblit tuner snd_timer font nvidia(P) snd_seq_device bitblit agpgart softcursor cx25840 snd vga16fb soundcore snd_page_alloc pvrusb2(-) dvb_core i2c_nforce2 vgastate lp parport cx2341x serio_raw v4l2_common joydev k8temp videodev v4l1_compat tveeprom usbhid hid usb_storage floppy forcedeth ahci pata_amd
[ 180.974486]
[ 180.974496] Pid: 804, comm: pvrusb2-context Tainted: P (2.6.32-22-generic #33-Ubuntu) .
[ 180.974504] EIP: 0060:[<00100100>] EFLAGS: 00010206 CPU: 0
[ 180.974512] EIP is at 0x100100
[ 180.974517] EAX: f690ac00 EBX: f690af00 ECX: 00000001 EDX: 00100100
[ 180.974524] ESI: f690ac04 EDI: e2ca3f98 EBP: e2ca3f88 ESP: e2ca3f74
[ 180.974530] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 180.974538] Process pvrusb2-context (pid: 804, ti=e2ca2000 task=e373c010 task.ti=e2ca2000)
[ 180.974544] Stack:
[ 180.974548] f8492d4c f84927f2 f690af00 f690af00 e373c010 e2ca3fb8 f8492e43 e373c2bc
[ 180.974562] <0> e373c010 00000000 e373c010 c0167740 e2ca3fa4 e2ca3fa4 e2ca1f04 00000000
[ 180.974577] <0> f8492e00 e2ca3fe0 c01674b4 00000000 00000000 00000000 e2ca3fcc e2ca3fcc
[ 180.974593] Call Trace:
[ 180.974623] [<f8492d4c>] ? pvr2_context_check+0x3c/0xf0 [pvrusb2]
[ 180.974647] [<f84927f2>] ? pvr2_context_set_notify+0xc2/0x100 [pvrusb2]
[ 180.974672] [<f8492e43>] ? pvr2_context_thread_func+0x43/0x1d0 [pvrusb2]
[ 180.974689] [<c0167740>] ? autoremove_wake_function+0x0/0x50
[ 180.974712] [<f8492e00>] ? pvr2_context_thread_func+0x0/0x1d0 [pvrusb2]
[ 180.974721] [<c01674b4>] ? kthread+0x74/0x80
[ 180.974729] [<c0167440>] ? kthread+0x0/0x80
[ 180.974739] [<c0104087>] ? kernel_thread_helper+0x7/0x10
[ 180.974744] Code: Bad EIP value.
[ 180.974750] EIP: [<00100100>] 0x100100 SS:ESP 0068:e2ca3f74
[ 180.974762] CR2: 0000000000100100
[ 180.974770] ---[ end trace 5100c461a7ceb6d2 ]---

[Thomas Mashos (tgm4883)]

We really do appreciate you opening this ticket to help improve Mythbuntu, but it needs to be closed for a number of reasons. The biggest one is that we have turned our efforts to a newer version. Could you please verify if this issue still exists in the latest version?

Please do not let the closing of this ticket dissuade you from opening a new ticket if this (or any other) problem occurs with the newer versions.