Video 4 Linux problems

khufu · 2014-07-15 20:17:06

Hi,

I went into this problem today using FFmpeg to record a webcam:
(Meesage from dmesg)

 208.455162] BUG: unable to handle kernel paging request at ffff8806e4960a30
[  208.455253] IP: [<ffffffffa0b15c02>] __vb2_queue_alloc+0x82/0x500 [videobuf2_core]
[  208.455374] Oops: 0002 [#1] PREEMPT SMP 
[  208.455425] Modules linked in: ctr ccm coretemp intel_rapl ecb x86_pkg_temp_thermal btusb mousedev joydev bluetooth uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev cdc_mbim media cdc_ncm usbnet intel_powerclamp mii cdc_wdm cdc_acm 6lowpan_iphc kvm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel aes_x86_64 arc4 lrw gf128mul snd_hda_codec_hdmi iwldvm mac80211 snd_hda_codec_conexant glue_helper mei_me snd_hda_codec_generic e1000e iTCO_wdt ablk_helper evdev serio_raw psmouse i2c_i801 cryptd mac_hid iTCO_vendor_support microcode i915 iwlwifi mei ac cfg80211 thermal wmi button snd_hda_intel thinkpad_acpi snd_hda_controller snd_hda_codec snd_hwdep tpm_tis nvram snd_pcm rfkill drm_kms_helper tpm hwmon drm intel_gtt snd_timer i2c_algo_bit battery video i2c_core
[  208.456334]  lpc_ich snd shpchp ptp processor pps_core soundcore ext4 crc16 mbcache jbd2 hid_logitech_dj usbhid hid sd_mod crc_t10dif crct10dif_common atkbd libps2 ahci libahci libata sdhci_pci sdhci ehci_pci led_class ehci_hcd scsi_mod mmc_core usbcore usb_common i8042 serio
[  208.456662] CPU: 0 PID: 1062 Comm: ffmpeg Not tainted 3.15.5-1-ARCH #1
[  208.456724] Hardware name: LENOVO 429137G/429137G, BIOS 8DET56WW (1.26 ) 12/01/2011
[  208.456794] task: ffff8801179d28c0 ti: ffff8800cb6a4000 task.ti: ffff8800cb6a4000
[  208.456862] RIP: 0010:[<ffffffffa0b15c02>]  [<ffffffffa0b15c02>] __vb2_queue_alloc+0x82/0x500 [videobuf2_core]
[  208.456959] RSP: 0018:ffff8800cb6a7bf8  EFLAGS: 00010287
[  208.457009] RAX: 00000000c2a60400 RBX: ffff8800cf65e8d8 RCX: ffff8800c2a60800
[  208.457074] RDX: 00000000c2a60421 RSI: 0000000000000000 RDI: ffffffff81b0e470
[  208.457138] RBP: ffff8800cb6a7c48 R08: ffff8800cf65e8d8 R09: ffffea000309eb40
[  208.457203] R10: 0000000000004ac7 R11: 000000000000001f R12: ffff8800c2a60800
[  208.457267] R13: 0000000000000001 R14: ffff8800cf65eabc R15: 0000000000000022
[  208.457333] FS:  00007f4f778cb780(0000) GS:ffff88011e200000(0000) knlGS:0000000000000000
[  208.457406] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  208.457459] CR2: ffff8806e4960a30 CR3: 00000000cf438000 CR4: 00000000000407f0
[  208.457524] Stack:
[  208.457545]  0000002100000000 ffff880000000001 0000000100000100 ffff8800c2a60800
[  208.457626]  ffff8800cf65e8d8 ffff8800cf65e8d8 ffff8800cf65eab8 ffff8800cf65ea78
[  208.457704]  ffff8800cb6a7db0 ffff8800cb6a7db8 ffff8800cb6a7c90 ffffffffa0b1829c
[  208.457784] Call Trace:
[  208.457816]  [<ffffffffa0b1829c>] __reqbufs.isra.12+0x15c/0x2d0 [videobuf2_core]
[  208.457888]  [<ffffffffa0b184e0>] vb2_reqbufs+0x30/0x40 [videobuf2_core]
[  208.457954]  [<ffffffffa0b2970e>] uvc_alloc_buffers+0x2e/0x50 [uvcvideo]
[  208.458020]  [<ffffffffa0b2b8bb>] uvc_v4l2_do_ioctl+0xe4b/0x14f0 [uvcvideo]
[  208.458090]  [<ffffffff8113f963>] ? unlock_page+0x23/0x30
[  208.458144]  [<ffffffff8116cb42>] ? do_read_fault.isra.59+0x1b2/0x2d0
[  208.458211]  [<ffffffffa0aed066>] video_usercopy+0x366/0x5f0 [videodev]
[  208.458275]  [<ffffffffa0b2aa70>] ? uvc_v4l2_set_streamparm.isra.7+0x1a0/0x1a0 [uvcvideo]
[  208.458353]  [<ffffffff815110dc>] ? __do_page_fault+0x2ec/0x600
[  208.458411]  [<ffffffffa0b29f3f>] uvc_v4l2_ioctl+0x2f/0x70 [uvcvideo]
[  208.458474]  [<ffffffffa0ae8894>] v4l2_ioctl+0x154/0x190 [videodev]
[  208.458535]  [<ffffffff811c7680>] do_vfs_ioctl+0x2d0/0x4b0
[  208.458588]  [<ffffffff811c78e1>] SyS_ioctl+0x81/0xa0
[  208.458639]  [<ffffffff81515fa9>] system_call_fastpath+0x16/0x1b
[  208.461477] Code: f8 41 89 04 24 8b 03 41 89 44 24 04 8b 45 b8 83 f8 01 41 89 44 24 3c 74 50 8b 83 50 01 00 00 41 8d 14 07 41 83 c7 01 44 3b 7d c0 <4c> 89 64 d3 50 0f 84 ae 02 00 00 8b 7b 38 be d0 80 00 00 e8 f6 
[  208.467676] RIP  [<ffffffffa0b15c02>] __vb2_queue_alloc+0x82/0x500 [videobuf2_core]
[  208.470725]  RSP <ffff8800cb6a7bf8>
[  208.473757] CR2: ffff8806e4960a30
[  208.488539] ---[ end trace f23b1b91a45a4512 ]---

Cant make out much, other than I have no clue where to go from here?

Last edited by khufu (2014-07-15 20:17:34)

ConnorBehan · 2014-07-16 05:22:55

Do other things work with the webcam like a simple "mplayer -tv driver=v4l2:device=/dev/video0 tv://"? Maybe the problem can be worked around by changing the flags for ffmpeg.

If not, it might be worth loading the "uvcvideo" module with different parameters. For example "quirks=1"?

sweetthdevil · 2014-07-16 07:23:32

Hi there is an issue with the kernel 3.15 see https://bbs.archlinux.org/viewtopic.php?id=183064

Downgrade to 3.14 until 3.16 is out.

khufu · 2014-07-16 07:45:15

Thank you #1 and #2

Arch Linux

#1 2014-07-15 20:17:06

Video 4 Linux problems

#2 2014-07-16 05:22:55

Re: Video 4 Linux problems

#3 2014-07-16 07:23:32

Re: Video 4 Linux problems

#4 2014-07-16 07:45:15

Re: Video 4 Linux problems

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