From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ee0-f42.google.com ([74.125.83.42]:48846 "EHLO mail-ee0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751543AbaANU4m (ORCPT ); Tue, 14 Jan 2014 15:56:42 -0500 Received: by mail-ee0-f42.google.com with SMTP id e49so474602eek.29 for ; Tue, 14 Jan 2014 12:56:41 -0800 (PST) Message-ID: <52D5A4D0.1020509@googlemail.com> Date: Tue, 14 Jan 2014 21:57:52 +0100 From: =?UTF-8?B?RnJhbmsgU2Now6RmZXI=?= MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: Linux Media Mailing List Subject: Re: [PATCH 3/7] em28xx: Only deallocate struct em28xx after finishing all extensions References: <1389567649-26838-1-git-send-email-m.chehab@samsung.com> <1389567649-26838-4-git-send-email-m.chehab@samsung.com> <52D4383B.6030304@googlemail.com> <20140113172334.191862a7@samsung.com> <52D460D8.1000807@googlemail.com> <20140114111054.58ede4a3@samsung.com> <52D57E2C.2070407@googlemail.com> <20140114165512.2d14af95@samsung.com> <20140114173121.1f06ec38@samsung.com> In-Reply-To: <20140114173121.1f06ec38@samsung.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Am 14.01.2014 20:31, schrieb Mauro Carvalho Chehab: > > Ok, patch 5 is not needed anymore. > > However, after a series of removals and re-inserts, I got these: > > > [120982.699455] ------------[ cut here ]------------ > [120982.699509] WARNING: CPU: 0 PID: 7953 at lib/list_debug.c:33 __list_add+0xac/0xc0() > [120982.699539] list_add corruption. prev->next should be next (ffff88019ffce4f8), but was 0000000d00000007. (prev=ffff880101dbfb48). > [120982.699566] Modules linked in: lgdt330x tuner_xc2028 tuner tvp5150 rc_hauppauge em28xx_rc rc_core xc5000 drxk em28xx_dvb dvb_core em28xx_alsa em28xx_v4l videobuf2_vmalloc videobuf2_memops videobuf2_core em28xx tveeprom v4l2_common videodev media netconsole usb_storage fuse ccm nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw bnep arc4 vfat fat iwldvm mac80211 iwlwifi cfg80211 x86_pkg_temp_thermal coretemp kvm_intel kvm crc32_pclmul crc32c_intel ghash_clmulni_intel > [120982.701828] snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm iTCO_wdt iTCO_vendor_support btusb bluetooth joydev microcode serio_raw r8169 mii i2c_i801 lpc_ich mfd_core rfkill snd_page_alloc snd_timer snd mei_me soundcore mei shpchp nfsd auth_rpcgss nfs_acl lockd sunrpc nouveau i915 ttm i2c_algo_bit drm_kms_helper drm i2c_core mxm_wmi wmi video [last unloaded: videobuf2_memops] > [120982.703581] CPU: 0 PID: 7953 Comm: xawtv Tainted: G D 3.13.0-rc1+ #24 > [120982.703610] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 550P5C/550P7C/SAMSUNG_NP1234567890, BIOS P04ABI.013.130220.dg 02/20/2013 > [120982.703638] 0000000000000009 ffff88011f63bb70 ffffffff816a03c6 ffff88011f63bbb8 > [120982.703794] ffff88011f63bba8 ffffffff8106aaad ffff88018cfb3f48 ffff88019ffce4f8 > [120982.703924] ffff880101dbfb48 0000000000000282 0000000000000000 ffff88011f63bc08 > [120982.704056] Call Trace: > [120982.704093] [] dump_stack+0x45/0x56 > [120982.704129] [] warn_slowpath_common+0x7d/0xa0 > [120982.704162] [] warn_slowpath_fmt+0x4c/0x50 > [120982.704197] [] __list_add+0xac/0xc0 > [120982.704233] [] buffer_queue+0x7b/0xb0 [em28xx_v4l] > [120982.704432] [] __enqueue_in_driver+0x74/0x80 [videobuf2_core] > [120982.704469] [] vb2_streamon+0xa0/0x140 [videobuf2_core] > [120982.704505] [] vb2_ioctl_streamon+0x48/0x50 [videobuf2_core] > [120982.704543] [] v4l_streamon+0x1a/0x20 [videodev] > [120982.704581] [] __video_do_ioctl+0x2a4/0x330 [videodev] > [120982.704619] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120982.704658] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120982.704719] [] video_usercopy+0x240/0x5d0 [videodev] > [120982.704756] [] ? trace_hardirqs_on+0xd/0x10 > [120982.704792] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120982.704829] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120982.704867] [] video_ioctl2+0x15/0x20 [videodev] > [120982.704903] [] v4l2_ioctl+0x123/0x160 [videodev] > [120982.704939] [] do_vfs_ioctl+0x300/0x520 > [120982.704974] [] ? file_has_perm+0x86/0xa0 > [120982.705006] [] SyS_ioctl+0x81/0xa0 > [120982.705039] [] system_call_fastpath+0x16/0x1b > [120982.705070] ---[ end trace 7e24c4fe20a76f18 ]--- > [120985.899453] ------------[ cut here ]------------ > [120985.899502] WARNING: CPU: 0 PID: 7953 at lib/list_debug.c:33 __list_add+0xac/0xc0() > [120985.899531] list_add corruption. prev->next should be next (ffff88019ffce4f8), but was (null). (prev=ffff88018cfb0348). > [120985.899559] Modules linked in: lgdt330x tuner_xc2028 tuner tvp5150 rc_hauppauge em28xx_rc rc_core xc5000 drxk em28xx_dvb dvb_core em28xx_alsa em28xx_v4l videobuf2_vmalloc videobuf2_memops videobuf2_core em28xx tveeprom v4l2_common videodev media netconsole usb_storage fuse ccm nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw bnep arc4 vfat fat iwldvm mac80211 iwlwifi cfg80211 x86_pkg_temp_thermal coretemp kvm_intel kvm crc32_pclmul crc32c_intel ghash_clmulni_intel > [120985.901761] snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm iTCO_wdt iTCO_vendor_support btusb bluetooth joydev microcode serio_raw r8169 mii i2c_i801 lpc_ich mfd_core rfkill snd_page_alloc snd_timer snd mei_me soundcore mei shpchp nfsd auth_rpcgss nfs_acl lockd sunrpc nouveau i915 ttm i2c_algo_bit drm_kms_helper drm i2c_core mxm_wmi wmi video [last unloaded: videobuf2_memops] > [120985.903502] CPU: 0 PID: 7953 Comm: xawtv Tainted: G D W 3.13.0-rc1+ #24 > [120985.903530] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 550P5C/550P7C/SAMSUNG_NP1234567890, BIOS P04ABI.013.130220.dg 02/20/2013 > [120985.903557] 0000000000000009 ffff88011f63bb70 ffffffff816a03c6 ffff88011f63bbb8 > [120985.903686] ffff88011f63bba8 ffffffff8106aaad ffff88018cfb0348 ffff88019ffce4f8 > [120985.903826] ffff88018cfb0348 0000000000000282 0000000000000000 ffff88011f63bc08 > [120985.903955] Call Trace: > [120985.903988] [] dump_stack+0x45/0x56 > [120985.904021] [] warn_slowpath_common+0x7d/0xa0 > [120985.904052] [] warn_slowpath_fmt+0x4c/0x50 > [120985.904083] [] __list_add+0xac/0xc0 > [120985.904116] [] buffer_queue+0x7b/0xb0 [em28xx_v4l] > [120985.904295] [] __enqueue_in_driver+0x74/0x80 [videobuf2_core] > [120985.904330] [] vb2_streamon+0xa0/0x140 [videobuf2_core] > [120985.904363] [] vb2_ioctl_streamon+0x48/0x50 [videobuf2_core] > [120985.904398] [] v4l_streamon+0x1a/0x20 [videodev] > [120985.904433] [] __video_do_ioctl+0x2a4/0x330 [videodev] > [120985.904470] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120985.904504] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120985.904540] [] video_usercopy+0x240/0x5d0 [videodev] > [120985.904575] [] ? trace_hardirqs_on+0xd/0x10 > [120985.904608] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120985.904641] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120985.904676] [] video_ioctl2+0x15/0x20 [videodev] > [120985.904710] [] v4l2_ioctl+0x123/0x160 [videodev] > [120985.904743] [] do_vfs_ioctl+0x300/0x520 > [120985.904780] [] ? file_has_perm+0x86/0xa0 > [120985.904810] [] SyS_ioctl+0x81/0xa0 > [120985.904843] [] system_call_fastpath+0x16/0x1b > [120985.904871] ---[ end trace 7e24c4fe20a76f19 ]--- > [120985.904896] ------------[ cut here ]------------ > [120985.904922] WARNING: CPU: 0 PID: 7953 at lib/list_debug.c:36 __list_add+0x8a/0xc0() > [120985.904953] list_add double add: new=ffff88018cfb0348, prev=ffff88018cfb0348, next=ffff88019ffce4f8. > [120985.904978] Modules linked in: lgdt330x tuner_xc2028 tuner tvp5150 rc_hauppauge em28xx_rc rc_core xc5000 drxk em28xx_dvb dvb_core em28xx_alsa em28xx_v4l videobuf2_vmalloc videobuf2_memops videobuf2_core em28xx tveeprom v4l2_common videodev media netconsole usb_storage fuse ccm nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw bnep arc4 vfat fat iwldvm mac80211 iwlwifi cfg80211 x86_pkg_temp_thermal coretemp kvm_intel kvm crc32_pclmul crc32c_intel ghash_clmulni_intel > [120985.907016] snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm iTCO_wdt iTCO_vendor_support btusb bluetooth joydev microcode serio_raw r8169 mii i2c_i801 lpc_ich mfd_core rfkill snd_page_alloc snd_timer snd mei_me soundcore mei shpchp nfsd auth_rpcgss nfs_acl lockd sunrpc nouveau i915 ttm i2c_algo_bit drm_kms_helper drm i2c_core mxm_wmi wmi video [last unloaded: videobuf2_memops] > [120985.908654] CPU: 0 PID: 7953 Comm: xawtv Tainted: G D W 3.13.0-rc1+ #24 > [120985.908680] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 550P5C/550P7C/SAMSUNG_NP1234567890, BIOS P04ABI.013.130220.dg 02/20/2013 > [120985.908707] 0000000000000009 ffff88011f63bb70 ffffffff816a03c6 ffff88011f63bbb8 > [120985.908988] ffff88011f63bba8 ffffffff8106aaad ffff88018cfb0348 ffff88019ffce4f8 > [120985.909110] ffff88018cfb0348 0000000000000282 0000000000000000 ffff88011f63bc08 > [120985.909230] Call Trace: > [120985.909268] [] dump_stack+0x45/0x56 > [120985.909305] [] warn_slowpath_common+0x7d/0xa0 > [120985.909336] [] warn_slowpath_fmt+0x4c/0x50 > [120985.909380] [] __list_add+0x8a/0xc0 > [120985.909410] [] buffer_queue+0x7b/0xb0 [em28xx_v4l] > [120985.909442] [] __enqueue_in_driver+0x74/0x80 [videobuf2_core] > [120985.909474] [] vb2_streamon+0xa0/0x140 [videobuf2_core] > [120985.909505] [] vb2_ioctl_streamon+0x48/0x50 [videobuf2_core] > [120985.909537] [] v4l_streamon+0x1a/0x20 [videodev] > [120985.909570] [] __video_do_ioctl+0x2a4/0x330 [videodev] > [120985.909604] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120985.909636] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120985.909670] [] video_usercopy+0x240/0x5d0 [videodev] > [120985.909702] [] ? trace_hardirqs_on+0xd/0x10 > [120985.909732] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120985.909764] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120985.909799] [] video_ioctl2+0x15/0x20 [videodev] > [120985.909830] [] v4l2_ioctl+0x123/0x160 [videodev] > [120985.909860] [] do_vfs_ioctl+0x300/0x520 > [120985.909890] [] ? file_has_perm+0x86/0xa0 > [120985.909918] [] SyS_ioctl+0x81/0xa0 > [120985.909948] [] system_call_fastpath+0x16/0x1b > [120985.909974] ---[ end trace 7e24c4fe20a76f1a ]--- > [120985.910186] ------------[ cut here ]------------ > [120985.910213] WARNING: CPU: 0 PID: 7953 at lib/list_debug.c:33 __list_add+0xac/0xc0() > [120985.910236] list_add corruption. prev->next should be next (ffff88019ffce4f8), but was ffff88018cfb0348. (prev=ffff88018cfb0348). > [120985.910257] Modules linked in: lgdt330x tuner_xc2028 tuner tvp5150 rc_hauppauge em28xx_rc rc_core xc5000 drxk em28xx_dvb dvb_core em28xx_alsa em28xx_v4l videobuf2_vmalloc videobuf2_memops videobuf2_core em28xx tveeprom v4l2_common videodev media netconsole usb_storage fuse ccm nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw bnep arc4 vfat fat iwldvm mac80211 iwlwifi cfg80211 x86_pkg_temp_thermal coretemp kvm_intel kvm crc32_pclmul crc32c_intel ghash_clmulni_intel > [120985.912159] snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm iTCO_wdt iTCO_vendor_support btusb bluetooth joydev microcode serio_raw r8169 mii i2c_i801 lpc_ich mfd_core rfkill snd_page_alloc snd_timer snd mei_me soundcore mei shpchp nfsd auth_rpcgss nfs_acl lockd sunrpc nouveau i915 ttm i2c_algo_bit drm_kms_helper drm i2c_core mxm_wmi wmi video [last unloaded: videobuf2_memops] > [120985.913642] CPU: 0 PID: 7953 Comm: xawtv Tainted: G D W 3.13.0-rc1+ #24 > [120985.913667] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 550P5C/550P7C/SAMSUNG_NP1234567890, BIOS P04ABI.013.130220.dg 02/20/2013 > [120985.913691] 0000000000000009 ffff88011f63bb70 ffffffff816a03c6 ffff88011f63bbb8 > [120985.913805] ffff88011f63bba8 ffffffff8106aaad ffff88018cfb3f48 ffff88019ffce4f8 > [120985.913920] ffff88018cfb0348 0000000000000282 0000000000000000 ffff88011f63bc08 > [120985.914035] Call Trace: > [120985.914063] [] dump_stack+0x45/0x56 > [120985.914093] [] warn_slowpath_common+0x7d/0xa0 > [120985.914121] [] warn_slowpath_fmt+0x4c/0x50 > [120985.914150] [] __list_add+0xac/0xc0 > [120985.914180] [] buffer_queue+0x7b/0xb0 [em28xx_v4l] > [120985.914353] [] __enqueue_in_driver+0x74/0x80 [videobuf2_core] > [120985.914385] [] vb2_streamon+0xa0/0x140 [videobuf2_core] > [120985.914416] [] vb2_ioctl_streamon+0x48/0x50 [videobuf2_core] > [120985.914449] [] v4l_streamon+0x1a/0x20 [videodev] > [120985.914482] [] __video_do_ioctl+0x2a4/0x330 [videodev] > [120985.914515] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120985.914548] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120985.914580] [] video_usercopy+0x240/0x5d0 [videodev] > [120985.914612] [] ? trace_hardirqs_on+0xd/0x10 > [120985.914643] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120985.914675] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120985.914708] [] video_ioctl2+0x15/0x20 [videodev] > [120985.914740] [] v4l2_ioctl+0x123/0x160 [videodev] > [120985.914770] [] do_vfs_ioctl+0x300/0x520 > [120985.914799] [] ? file_has_perm+0x86/0xa0 > [120985.914828] [] SyS_ioctl+0x81/0xa0 > [120985.914857] [] system_call_fastpath+0x16/0x1b > [120985.914884] ---[ end trace 7e24c4fe20a76f1b ]--- > [120991.576999] em2882/3 #0: submit of audio urb failed > [120991.781651] ------------[ cut here ]------------ > [120991.781700] WARNING: CPU: 0 PID: 7979 at lib/list_debug.c:33 __list_add+0xac/0xc0() > [120991.781730] list_add corruption. prev->next should be next (ffff88019ffce4f8), but was (null). (prev=ffff88018cfb1b48). > [120991.781756] Modules linked in: lgdt330x tuner_xc2028 tuner tvp5150 rc_hauppauge em28xx_rc rc_core xc5000 drxk em28xx_dvb dvb_core em28xx_alsa em28xx_v4l videobuf2_vmalloc videobuf2_memops videobuf2_core em28xx tveeprom v4l2_common videodev media netconsole usb_storage fuse ccm nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw bnep arc4 vfat fat iwldvm mac80211 iwlwifi cfg80211 x86_pkg_temp_thermal coretemp kvm_intel kvm crc32_pclmul crc32c_intel ghash_clmulni_intel > [120991.783977] snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm iTCO_wdt iTCO_vendor_support btusb bluetooth joydev microcode serio_raw r8169 mii i2c_i801 lpc_ich mfd_core rfkill snd_page_alloc snd_timer snd mei_me soundcore mei shpchp nfsd auth_rpcgss nfs_acl lockd sunrpc nouveau i915 ttm i2c_algo_bit drm_kms_helper drm i2c_core mxm_wmi wmi video [last unloaded: videobuf2_memops] > [120991.785750] CPU: 0 PID: 7979 Comm: tvtime Tainted: G D W 3.13.0-rc1+ #24 > [120991.785779] Hardware name: SAMSUNG ELECTRONICS CO., LTD. 550P5C/550P7C/SAMSUNG_NP1234567890, BIOS P04ABI.013.130220.dg 02/20/2013 > [120991.785806] 0000000000000009 ffff88001254fb70 ffffffff816a03c6 ffff88001254fbb8 > [120991.785938] ffff88001254fba8 ffffffff8106aaad ffff88018cfb3f48 ffff88019ffce4f8 > [120991.786102] ffff88018cfb1b48 0000000000000282 0000000000000000 ffff88001254fc08 > [120991.786233] Call Trace: > [120991.786268] [] dump_stack+0x45/0x56 > [120991.786319] [] warn_slowpath_common+0x7d/0xa0 > [120991.786359] [] warn_slowpath_fmt+0x4c/0x50 > [120991.786393] [] __list_add+0xac/0xc0 > [120991.786429] [] buffer_queue+0x7b/0xb0 [em28xx_v4l] > [120991.786619] [] __enqueue_in_driver+0x74/0x80 [videobuf2_core] > [120991.786656] [] vb2_streamon+0xa0/0x140 [videobuf2_core] > [120991.786690] [] vb2_ioctl_streamon+0x48/0x50 [videobuf2_core] > [120991.786728] [] v4l_streamon+0x1a/0x20 [videodev] > [120991.786767] [] __video_do_ioctl+0x2a4/0x330 [videodev] > [120991.786804] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120991.786841] [] ? v4l_dbg_s_register+0x150/0x150 [videodev] > [120991.786880] [] video_usercopy+0x240/0x5d0 [videodev] > [120991.786917] [] ? trace_hardirqs_on+0xd/0x10 > [120991.786952] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120991.786988] [] ? v4l2_ioctl+0x5b/0x160 [videodev] > [120991.787027] [] video_ioctl2+0x15/0x20 [videodev] > [120991.787063] [] v4l2_ioctl+0x123/0x160 [videodev] > [120991.787098] [] do_vfs_ioctl+0x300/0x520 > [120991.787133] [] ? file_has_perm+0x86/0xa0 > [120991.787165] [] SyS_ioctl+0x81/0xa0 > [120991.787199] [] system_call_fastpath+0x16/0x1b > [120991.787230] ---[ end trace 7e24c4fe20a76f1c ]--- Nice. :/ Maybe it's time to check the videobuf2 handling.