em28xx causes NULL pointer warning in videobuf2-core.c
Lars Ljung <[email protected]> Thu, 30 Jul 2026 19:08:51 +0200
| Newsgroups | org.kernel.vger.linux-media |
|---|---|
| Message-ID | <[email protected]> |
Hi, While trying to get an old Pinnacle PCTV USB 2 to work I got a warning message in the log. See the attached file. This is on Ubuntu, kernel version 7.0.0-28. The problem seems to be the second call to vb2_queue_init() in em28xx_vb2_setup(). This call should only be made if VBI is supported, right? I modified em28xx_vb2_setup() to use em28xx_vbi_supported() to check if VBI is supported. That did silence the warning message. My hardware still does not work, so that must be caused by something else. Kind regards, Lars Ljung
em28xx.log
(text/x-log, 11.1 KB)
jul 29 18:30:42 kernel: usb 3-1: new high-speed USB device number 10 using xhci_hcd jul 29 18:30:42 kernel: usb 3-1: New USB device found, idVendor=2304, idProduct=0208, bcdDevice= 1.00 jul 29 18:30:42 kernel: usb 3-1: New USB device strings: Mfr=2, Product=1, SerialNumber=0 jul 29 18:30:42 kernel: usb 3-1: Product: PCTV USB2 PAL/SECAM jul 29 18:30:42 kernel: usb 3-1: Manufacturer: Pinnacle Systems GmbH jul 29 18:30:42 kernel: em28xx 3-1:1.0: New device Pinnacle Systems GmbH PCTV USB2 PAL/SECAM @ 480 Mbps (2304:0208, interface 0, class 0) jul 29 18:30:42 kernel: em28xx 3-1:1.0: Video interface 0 found: bulk isoc jul 29 18:30:42 kernel: em28xx 3-1:1.0: chip ID is em2710/2820 jul 29 18:30:42 kernel: em28xx 3-1:1.0: EEPROM ID = 1a eb 67 95, EEPROM hash = 0x832b1b67 jul 29 18:30:42 kernel: em28xx 3-1:1.0: EEPROM info: jul 29 18:30:42 kernel: em28xx 3-1:1.0: AC97 audio (5 sample rates) jul 29 18:30:42 kernel: em28xx 3-1:1.0: 500mA max power jul 29 18:30:42 kernel: em28xx 3-1:1.0: Table at offset 0x06, strings=0x2a98, 0x2e6a, 0x0000 jul 29 18:30:42 kernel: em28xx 3-1:1.0: Identified as Pinnacle PCTV USB 2 (card=3) jul 29 18:30:42 kernel: em28xx 3-1:1.0: analog set to isoc mode. jul 29 18:30:42 kernel: em28xx 3-1:1.1: audio device (2304:0208): interface 1, class 1 jul 29 18:30:42 kernel: em28xx 3-1:1.2: audio device (2304:0208): interface 2, class 1 jul 29 18:30:42 kernel: usbcore: registered new interface driver em28xx jul 29 18:30:42 kernel: em28xx 3-1:1.0: Registering V4L2 extension jul 29 18:30:42 kernel: usbcore: registered new interface driver snd-usb-audio jul 29 18:30:42 kernel: saa7115 16-0025: saa7113 found @ 0x4a (3-1:1.0) jul 29 18:30:43 kernel: tda9887 16-0043: creating new instance jul 29 18:30:43 kernel: tda9887 16-0043: tda988[5/6/7] found jul 29 18:30:43 kernel: tuner: 16-0043: Tuner 74 found with type(s) Radio TV. jul 29 18:30:43 kernel: tuner: 16-0063: Tuner -1 found with type(s) Radio TV. jul 29 18:30:43 kernel: tuner-simple 16-0063: creating new instance jul 29 18:30:43 kernel: tuner-simple 16-0063: type set to 37 (LG PAL (newer TAPC series)) jul 29 18:30:43 kernel: em28xx 3-1:1.0: Config register raw data: 0x10 jul 29 18:30:43 kernel: em28xx 3-1:1.0: AC97 vendor ID = 0xffffffff jul 29 18:30:43 kernel: em28xx 3-1:1.0: AC97 features = 0x6a90 jul 29 18:30:43 kernel: em28xx 3-1:1.0: Empia 202 AC97 audio processor detected jul 29 18:30:44 kernel: em28xx 3-1:1.0: V4L2 video device registered as video4 jul 29 18:30:44 kernel: ------------[ cut here ]------------ jul 29 18:30:44 kernel: WARNING: drivers/media/common/videobuf2/videobuf2-core.c:2645 at vb2_core_queue_init+0x247/0x260 [videobuf2_common], CPU#3: modprobe/190232 jul 29 18:30:44 kernel: Modules linked in: tuner_simple tuner_types tda9887 tda8290 tuner snd_usb_audio saa7115 snd_usbmidi_lib em28xx_v4l(+) snd_ump em28xx tveeprom usbhid ccm rfcomm snd_seq_dummy snd_hrtimer cmac algif_hash algif_skcipher af_alg qrtr snd_ctl_led snd_soc_skl_hda_dsp snd_soc_intel_sof_board_helpers snd_sof_probes snd_soc_intel_hda_dsp_common bnep snd_hda_codec_intelhdmi snd_hda_codec_hdmi snd_hda_codec_alc269 snd_hda_codec_realtek_lib snd_hda_scodec_component snd_hda_codec_generic snd_soc_dmic snd_hda_intel snd_sof_pci_intel_tgl ip6t_REJECT snd_sof_pci_intel_cnl nf_reject_ipv6 snd_sof_intel_hda_generic xt_hl soundwire_intel ip6t_rt snd_sof_intel_hda_sdw_bpt snd_sof_intel_hda_common snd_soc_hdac_hda ipt_REJECT snd_sof_intel_hda_mlink nf_reject_ipv4 snd_sof_intel_hda xt_LOG soundwire_cadence nf_log_syslog snd_sof_pci nft_limit snd_sof_xtensa_dsp snd_sof xt_limit snd_sof_utils xt_addrtype snd_soc_acpi_intel_match xt_tcpudp snd_soc_acpi_intel_sdca_quirks soundwire_generic_allocation xt_conntrack snd_soc_sdw_utils jul 29 18:30:44 kernel: nf_conntrack snd_soc_acpi nf_defrag_ipv6 soundwire_bus nf_defrag_ipv4 snd_soc_sdca nft_compat crc8 x_tables snd_soc_avs binfmt_misc nf_tables snd_soc_hda_codec snd_hda_ext_core intel_uncore_frequency snd_hda_codec intel_uncore_frequency_common snd_hda_core xe snd_intel_dspcfg snd_intel_sdw_acpi snd_hwdep snd_soc_core x86_pkg_temp_thermal snd_compress intel_powerclamp drm_gpusvm_helper ac97_bus coretemp snd_pcm_dmaengine gpu_sched drm_gpuvm snd_pcm drm_ttm_helper kvm_intel drm_exec drm_suballoc_helper snd_seq_midi kvm snd_seq_midi_event uvcvideo iwlmvm irqbypass btusb snd_rawmidi btmtk videobuf2_vmalloc ghash_clmulni_intel processor_thermal_device_pci_legacy mac80211 nls_iso8859_1 hid_sensor_als snd_seq btrtl cmdlinepart uvc spi_nor aesni_intel processor_thermal_device hid_sensor_trigger btbcm videobuf2_memops ee1004 mei_hdcp mei_pxp mtd hp_bioscfg rapl snd_seq_device videobuf2_v4l2 libarc4 processor_thermal_wt_hint iosm btintel kfifo_buf intel_rapl_msr i2c_i801 firmware_attributes_class snd_timer jul 29 18:30:44 kernel: videobuf2_common intel_cstate mei_me i915 wwan platform_temperature_control iwlwifi i2c_smbus hid_sensor_iio_common spi_intel_pci snd bluetooth hp_wmi videodev wmi_bmof mc gnss processor_thermal_soc_slider industrialio mei i2c_mux spi_intel cfg80211 drm_buddy soundcore processor_thermal_rfim processor_thermal_rapl ttm intel_rapl_common intel_pmc_core processor_thermal_wt_req processor_thermal_power_floor pmt_telemetry drm_display_helper processor_thermal_mbox int3403_thermal cec pmt_discovery int340x_thermal_zone pmt_class rc_core intel_soc_dts_iosf int3400_thermal intel_hid intel_pmc_ssram_telemetry sparse_keymap wireless_hotkey i2c_algo_bit platform_profile acpi_thermal_rel acpi_pad intel_vsec igen6_edac joydev input_leds mac_hid sch_fq_codel lp ppdev msr parport efi_pstore nfnetlink dmi_sysfs autofs4 r8153_ecm cdc_ether usbnet r8152 mii hid_sensor_hub intel_ishtp_hid ucsi_acpi typec_ucsi typec nvme hid_multitouch nvme_core hid_generic nvme_keyring i2c_hid_acpi nvme_auth serio_raw i2c_hid hkdf video jul 29 18:30:44 kernel: intel_lpss_pci hid intel_lpss pinctrl_tigerlake wmi thunderbolt intel_ish_ipc idma64 intel_ishtp vmd jul 29 18:30:44 kernel: CPU: 3 UID: 0 PID: 190232 Comm: modprobe Tainted: G U 7.0.0-28-generic #28-Ubuntu PREEMPT(lazy) jul 29 18:30:44 kernel: Tainted: [U]=USER jul 29 18:30:44 kernel: Hardware name: HP HP EliteBook 850 G8 Notebook PC/8846, BIOS T76 Ver. 01.24.02 05/04/2026 jul 29 18:30:44 kernel: RIP: 0010:vb2_core_queue_init+0x247/0x260 [videobuf2_common] jul 29 18:30:44 kernel: Code: 31 ff 45 31 c0 c3 cc cc cc cc 0f 0b eb e7 0f 0b eb e3 0f 0b eb df 0f 0b eb db 0f 0b eb d7 0f 0b eb d3 0f 0b eb cf 0f 0b eb cb <0f> 0b eb c7 0f 0b eb c3 0f 0b eb bf 66 90 66 66 2e 0f 1f 84 00 00 jul 29 18:30:44 kernel: RSP: 0018:ffffcf35e581b850 EFLAGS: 00010246 jul 29 18:30:44 kernel: RAX: 0000000000000020 RBX: ffff8ca57b833100 RCX: 0000000000000001 jul 29 18:30:44 kernel: RDX: 0000000000000001 RSI: 0000000000000007 RDI: 0000000000000004 jul 29 18:30:44 kernel: RBP: ffffcf35e581b868 R08: ffff8ca57b833100 R09: 0000000000000000 jul 29 18:30:44 kernel: R10: ffff8ca324800000 R11: 0000000000000000 R12: ffff8ca57b832010 jul 29 18:30:44 kernel: R13: ffff8ca324801260 R14: ffff8ca57b832000 R15: ffff8ca57b832088 jul 29 18:30:44 kernel: FS: 000072e3698203c0(0000) GS:ffff8caae237f000(0000) knlGS:0000000000000000 jul 29 18:30:44 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 jul 29 18:30:44 kernel: CR2: 0000095400063fe0 CR3: 0000000439d91003 CR4: 0000000000f72ef0 jul 29 18:30:44 kernel: PKRU: 55555554 jul 29 18:30:44 kernel: Call Trace: jul 29 18:30:44 kernel: <TASK> jul 29 18:30:44 kernel: ? vb2_queue_init_name+0x12d/0x170 [videobuf2_v4l2] jul 29 18:30:44 kernel: ? fe_standby+0x1a/0x30 [tuner] jul 29 18:30:44 kernel: vb2_queue_init+0x10/0x20 [videobuf2_v4l2] jul 29 18:30:44 kernel: em28xx_v4l2_init.cold+0x11c8/0x11fd [em28xx_v4l] jul 29 18:30:44 kernel: ? __pfx_em28xx_video_register+0x10/0x10 [em28xx_v4l] jul 29 18:30:44 kernel: em28xx_register_extension+0x84/0xe0 [em28xx] jul 29 18:30:44 kernel: em28xx_video_register+0x15/0xff0 [em28xx_v4l] jul 29 18:30:44 kernel: do_one_initcall+0x59/0x350 jul 29 18:30:44 kernel: do_init_module+0x8b/0x290 jul 29 18:30:44 kernel: load_module+0x855/0x960 jul 29 18:30:44 kernel: init_module_from_file+0xfb/0x180 jul 29 18:30:44 kernel: idempotent_init_module+0x10e/0x300 jul 29 18:30:44 kernel: __x64_sys_finit_module+0x73/0xf0 jul 29 18:30:44 kernel: x64_sys_call+0xe2e/0x2390 jul 29 18:30:44 kernel: do_syscall_64+0x105/0x5a0 jul 29 18:30:44 kernel: ? vfs_read+0x179/0x3a0 jul 29 18:30:44 kernel: ? vfs_read+0x179/0x3a0 jul 29 18:30:44 kernel: ? restore_fpregs_from_fpstate+0x46/0xe0 jul 29 18:30:44 kernel: ? switch_fpu_return+0x64/0x110 jul 29 18:30:44 kernel: ? arch_exit_to_user_mode_prepare.isra.0+0xc3/0xe0 jul 29 18:30:44 kernel: ? do_syscall_64+0x140/0x5a0 jul 29 18:30:44 kernel: ? __fput+0x1a2/0x2d0 jul 29 18:30:44 kernel: ? fput_close_sync+0x40/0xc0 jul 29 18:30:44 kernel: ? __x64_sys_close+0x3e/0x90 jul 29 18:30:44 kernel: ? arch_exit_to_user_mode_prepare.isra.0+0xd/0xe0 jul 29 18:30:44 kernel: ? do_syscall_64+0x140/0x5a0 jul 29 18:30:44 kernel: ? ksys_read+0x71/0xf0 jul 29 18:30:44 kernel: ? arch_exit_to_user_mode_prepare.isra.0+0xd/0xe0 jul 29 18:30:44 kernel: ? do_syscall_64+0x140/0x5a0 jul 29 18:30:44 kernel: ? fput_close_sync+0x40/0xc0 jul 29 18:30:44 kernel: ? __x64_sys_close+0x3e/0x90 jul 29 18:30:44 kernel: ? arch_exit_to_user_mode_prepare.isra.0+0xd/0xe0 jul 29 18:30:44 kernel: ? do_syscall_64+0x140/0x5a0 jul 29 18:30:44 kernel: ? clear_bhb_loop+0x50/0xa0 jul 29 18:30:44 kernel: ? clear_bhb_loop+0x50/0xa0 jul 29 18:30:44 kernel: ? clear_bhb_loop+0x50/0xa0 jul 29 18:30:44 kernel: ? clear_bhb_loop+0x50/0xa0 jul 29 18:30:44 kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e jul 29 18:30:44 kernel: RIP: 0033:0x72e368f3cbad jul 29 18:30:44 kernel: Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 23 a2 0d 00 f7 d8 64 89 01 48 jul 29 18:30:44 kernel: RSP: 002b:00007ffe14360148 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 jul 29 18:30:44 kernel: RAX: ffffffffffffffda RBX: 0000587ba0fb4960 RCX: 000072e368f3cbad jul 29 18:30:44 kernel: RDX: 0000000000000004 RSI: 0000587b6164598b RDI: 0000000000000000 jul 29 18:30:44 kernel: RBP: 00007ffe143601e0 R08: 0000000000000000 R09: 0000000000000000 jul 29 18:30:44 kernel: R10: 0000000000000000 R11: 0000000000000246 R12: 0000587b6164598b jul 29 18:30:44 kernel: R13: 0000587ba0fb4a90 R14: 0000000000040000 R15: 0000000000000000 jul 29 18:30:44 kernel: </TASK> jul 29 18:30:44 kernel: ---[ end trace 0000000000000000 ]--- jul 29 18:30:44 kernel: em28xx 3-1:1.0: V4L2 extension successfully initialized jul 29 18:30:44 kernel: em28xx: Registered (Em28xx v4l2 Extension) extension jul 29 18:30:44 kernel: em28xx 3-1:1.0: Registering input extension jul 29 18:30:44 kernel: Registered IR keymap rc-pinnacle-grey jul 29 18:30:44 kernel: rc rc0: Pinnacle PCTV USB 2 as /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1:1.0/rc/rc0 jul 29 18:30:44 kernel: rc rc0: lirc_dev: driver em28xx registered at minor = 0, scancode receiver, no transmitter jul 29 18:30:44 kernel: input: Pinnacle PCTV USB 2 as /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1:1.0/rc/rc0/input27 jul 29 18:30:44 kernel: em28xx 3-1:1.0: Input extension successfully initialized jul 29 18:30:44 kernel: em28xx: Registered (Em28xx Input Extension) extension