On 05.02.2011 22:25, Andy Walls wrote:
> On Sat, 2011-02-05 at 16:45 +0100, Sven Barth wrote:
>> Hello together!
>>
>> I was eager to test my patch for cx25840 that was included in 2.6.37, so
>> I've updated my system and plugged in my Grabster AV400. But this
>> resulted in a "kernel bug" printed to dmesg:
>>
>> ==== dmesg begin ====
>>
>> usb 1-5: new high speed USB device using ehci_hcd and address 6
>> Linux video capture interface: v2.00
>> pvrusb2: Hardware description: Terratec Grabster AV400
>> pvrusb2: **********
>> pvrusb2: WARNING: Support for this device (Terratec Grabster AV400) is
>> experimental.
>> pvrusb2: Important functionality might not be entirely working.
>> pvrusb2: Please consider contacting the driver author to help with
>> further stabilization of the driver.
>> pvrusb2: **********
>> usb 1-5: USB disconnect, address 6
>> usbcore: registered new interface driver pvrusb2
>> pvrusb2: 20110116 (from www.isely.net):Hauppauge WinTV-PVR-USB2 MPEG2
>> Encoder/Tuner
>> pvrusb2: Debug mask is 31 (0x1f)
>> pvrusb2: Failed to submit write-control URB status=-19
>> pvrusb2: Device being rendered inoperable
>> pvrusb2: ***WARNING*** pvrusb2 device hardware appears to be jammed and
>> I can't clear it.
>> pvrusb2: You might need to power cycle the pvrusb2 device in order to
>> recover.
>> usb 1-5: new high speed USB device using ehci_hcd and address 7
>> pvrusb2: Hardware description: Terratec Grabster AV400
>> pvrusb2: **********
>> pvrusb2: WARNING: Support for this device (Terratec Grabster AV400) is
>> experimental.
>> pvrusb2: Important functionality might not be entirely working.
>> pvrusb2: Please consider contacting the driver author to help with
>> further stabilization of the driver.
>> pvrusb2: **********
>> cx25840 6-0044: cx25837-3 found @ 0x88 (pvrusb2_a)
>> ------------[ cut here ]------------
>> kernel BUG at drivers/media/video/v4l2-ctrls.c:1143!
>> invalid opcode: 0000 [#1] PREEMPT SMP
>> last sysfs file:
>> /sys/devices/pci0000:00/0000:00:02.2/usb1/1-5/i2c-6/6-0044/uevent
>> CPU 1
>> Modules linked in: cx25840 pvrusb2 dvb_core cx2341x v4l2_common videodev
>> v4l1_compat v4l2_compat_ioctl32 tveeprom ipv6 xfs exportfs ext2 radeon
>> snd_emu10k1 snd_intel8x0 ohci_hcd snd_rawmidi snd_ac97_codec ttm
>> drm_kms_helper ac97_bus snd_seq_dummy skge ehci_hcd snd_seq_oss
>> snd_seq_midi_event snd_seq snd_util_mem snd_seq_device snd_pcm_oss
>> snd_hwdep snd_mixer_oss snd_pcm snd_timer emu10k1_gp drm i2c_algo_bit
>> shpchp snd i2c_nforce2 soundcore usbcore processor pci_hotplug i2c_core
>> parport_pc snd_page_alloc floppy serio_raw button psmouse ns558
>> edac_core ppdev k8temp edac_mce_amd evdev sg analog lp gameport pcspkr
>> parport ext4 mbcache jbd2 crc16 sd_mod sr_mod cdrom sata_nv pata_acpi
>> sata_sil24 pata_amd libata scsi_mod raid1 md_mod
>>
>> Pid: 2184, comm: pvrusb2-context Not tainted 2.6.37-ARCH #1 nForce/
>> RIP: 0010:[<ffffffffa020b352>] [<ffffffffa020b352>]
>> v4l2_ctrl_cluster+0x32/0x40 [videodev]
>> RSP: 0018:ffff880033c61a30 EFLAGS: 00010246
>> RAX: 0000000000000001 RBX: ffff880038065800 RCX: 0000000000000001
>> RDX: 0000000000000000 RSI: ffff880039de1ee0 RDI: 0000000000000002
>> RBP: ffff880033c61a30 R08: 2222222222222222 R09: 2222222222222222
>> R10: 0000000000000000 R11: 0000000000000000 R12: ffff880039de1e78
>> R13: 0000000000008373 R14: ffff880039de1e00 R15: 00000000000000ed
>> FS: 00007f05b98a8700(0000) GS:ffff88003fd00000(0000)
knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
>> CR2: 00007fff6c8c5fe0 CR3: 000000003c89b000 CR4: 00000000000006e0
>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
>> Process pvrusb2-context (pid: 2184, threadinfo ffff880033c60000, task
>> ffff88003f8ada30)
>> Stack:
>> ffff880033c61aa0 ffffffffa0310b99 ffff880000000000 ffff88003c99e3fc
>> ffff880033c61ab0 ffffffff00000000 0000000000000200 ffff880039de1e08
>> ffff880033c61ac0 ffff880038065828 ffffffffa0318590 ffffffffa0318540
>> Call Trace:
>> [<ffffffffa0310b99>] cx25840_probe+0x479/0x840 [cx25840]
>> [<ffffffffa0308694>] i2c_device_probe+0x94/0xd0 [i2c_core]
>> [<ffffffff812b0f0a>] ? driver_sysfs_add+0x7a/0xb0
>> [<ffffffff812b11e6>] driver_probe_device+0x96/0x1c0
>> [<ffffffff812b13b0>] ? __device_attach+0x0/0x60
>> [<ffffffff812b13fb>] __device_attach+0x4b/0x60
>> [<ffffffff812afdd4>] bus_for_each_drv+0x64/0x90
>> [<ffffffff812b107f>] device_attach+0x8f/0xb0
>> [<ffffffff812b0805>] bus_probe_device+0x25/0x40
>> [<ffffffff812ae574>] device_add+0x4e4/0x5c0
>> [<ffffffff812ba941>] ? pm_runtime_init+0xd1/0xe0
>> [<ffffffff812ae669>] device_register+0x19/0x20
>> [<ffffffffa03091d5>] i2c_new_device+0x145/0x250 [i2c_core]
>> [<ffffffffa00b77b6>] v4l2_i2c_new_subdev_board+0x96/0x240
[v4l2_common]
>> [<ffffffffa00b79e3>] v4l2_i2c_new_subdev_cfg+0x83/0xb0 [v4l2_common]
>> [<ffffffffa0363760>] ? pvr2_context_notify+0x0/0x10 [pvrusb2]
>> [<ffffffffa0363760>] ? pvr2_context_notify+0x0/0x10 [pvrusb2]
>> [<ffffffffa035b606>] pvr2_hdw_initialize+0x346/0x1060 [pvrusb2]
>> [<ffffffffa036394b>] pvr2_context_thread_func+0x9b/0x320 [pvrusb2]
>> [<ffffffffa03638b0>] ? pvr2_context_thread_func+0x0/0x320 [pvrusb2]
>> [<ffffffff81077db0>] ? autoremove_wake_function+0x0/0x40
>> [<ffffffff813a6dc2>] ? _raw_spin_unlock_irqrestore+0x32/0x40
>> [<ffffffffa03638b0>] ? pvr2_context_thread_func+0x0/0x320 [pvrusb2]
>> [<ffffffff81077826>] kthread+0x96/0xa0
>> [<ffffffff8100cd24>] kernel_thread_helper+0x4/0x10
>> [<ffffffff81077790>] ? kthread+0x0/0xa0
>> [<ffffffff8100cd20>] ? kernel_thread_helper+0x0/0x10
>> Code: e5 74 28 31 c0 85 ff 74 20 48 63 d0 48 8d 14 d6 48 8b 0a 48 85 c9
>> 74 0a 48 89 71 18 48 8b 12 89 7a 20 83 c0 01 39 f8 72 e0 c9 c3<0f> 0b
>> 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 c7 c2 e0 ff 20
>> RIP [<ffffffffa020b352>] v4l2_ctrl_cluster+0x32/0x40 [videodev]
>> RSP<ffff880033c61a30>
>> ---[ end trace f2fe4d11aa83a3aa ]---
>>
>> ==== dmesg end ====
>>
>> I have pinpointed the problem to the following part of cx25840_probe in
>> cx25840-core.c:
>>
>> ==== source begin =====
>> sd->ctrl_handler =&state->hdl;
>> if (state->hdl.error) {
>> int err = state->hdl.error;
>>
>> v4l2_ctrl_handler_free(&state->hdl);
>> kfree(state);
>> return err;
>> }
>> v4l2_ctrl_cluster(2,&state->volume); //<= here the crash
occurs
>> v4l2_ctrl_handler_setup(&state->hdl);
>> ==== source end ====
>>
>> I have added a "if (!is_cx2583x(state))" check before the marked line
>> and now the probing (and my device) works. If this is the correct
>> solution for this problem I'll prepare a mail containing a patch. If not
>> feel free to propose a better solution.
>
> That is the correct solution. Please prepare and submit a patch.
>
Ok, will do.
> Note that in the logic a few lines above where the problem call happens,
> a volume and mute control were intentionally not created for CX2583x
> chips.
>
>
>> Note: This is a regression as the module used to work in 2.6.35 together
>> with the AV400 (I haven't tested 2.6.36 though).
>
> Yes 2.6.36 also has the new control framework change and the bug.
> Kernel 2.6.36 is also missing this other patch for cx25840 devices with
> a volume control:
>
>
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=f23b7952d37c69c0caa6c8dfb85dbf2eb9e5fcaa
>
> which reminds me, I have to send a request to get that back into
> 2.6.36-stable.
>
>
>> Regards,
>> Sven
>>
>> PS: Is there a way to get the source file and line of a dmesg "kernel
>> bug" report?
>
> Yes. If one reads the log carefully, one may notice...
>
>> kernel BUG at drivers/media/video/v4l2-ctrls.c:1143
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> ;)
This is one of those moments when I should bump my head against the next
wall...
>
> Also, since the report calls out
> function_name+current_offset/function_end_offset [module_name]:
>
>> RIP: 0010:[<ffffffffa020b352>] [<ffffffffa020b352>]
>> v4l2_ctrl_cluster+0x32/0x40 [videodev]
> [...]
>> [<ffffffffa0310b99>] cx25840_probe+0x479/0x840 [cx25840]
>
> one could do something like:
>
> $ objdump -d -l
/lib/modules/2.6.37-ARCH/kernel/drivers/media/video/videodev.ko | less
> $ objdump -d -l
/lib/modules/2.6.37-ARCH/kernel/drivers/media/video/cx25840/cx25840.ko |
less
>
> to find the source file and line.
Thank you for your explanation.
Regards,
Sven
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