Missing additional V4L2 caps in cx18

Hi,

We received a report of a backtrace from v4l2 with the cx18 module:

[    6.229393] ------------[ cut here ]------------
[    6.229414] WARNING: CPU: 1 PID: 593 at drivers/media/v4l2-core/v4l2-ioctl.c:1025 v4l_querycap+0x41/0x70 [videodev]()
[    6.229415] Modules linked in: cx18_alsa mxl5005s s5h1409 tuner_simple tuner_types cs5345 tuner intel_rapl iosf_mbi x86_pkg_temp_thermal coretemp raid1 snd_hda_codec_realtek kvm_intel snd_hda_codec_generic snd_hda_codec_hdmi kvm snd_oxygen(+) snd_hda_intel snd_oxygen_lib snd_hda_controller snd_hda_codec snd_mpu401_uart iTCO_wdt snd_rawmidi iTCO_vendor_support snd_hwdep crct10dif_pclmul crc32_pclmul crc32c_intel snd_seq cx18 snd_seq_device ghash_clmulni_intel videobuf_vmalloc tveeprom cx2341x snd_pcm serio_raw videobuf_core vfat dvb_core fat v4l2_common snd_timer videodev snd lpc_ich i2c_i801 joydev mfd_core mei_me media soundcore tpm_infineon soc_button_array tpm_tis mei shpchp tpm nfsd auth_rpcgss nfs_acl lockd grace sunrpc binfmt_misc i915 nouveau mxm_wmi wmi e1000e ttm i2c_algo_bit drm_kms_helper
[    6.229444]  drm ptp pps_core video
[    6.229446] CPU: 1 PID: 593 Comm: v4l_id Not tainted 3.19.3-200.fc21.x86_64 #1
[    6.229447] Hardware name: Gigabyte Technology Co., Ltd. Z87-D3HP/Z87-D3HP-CF, BIOS F6 01/20/2014
[    6.229448]  0000000000000000 00000000d12b1131 ffff88042dacfc28 ffffffff8176e215
[    6.229449]  0000000000000000 0000000000000000 ffff88042dacfc68 ffffffff8109bc1a
[    6.229451]  ffffffffa0594000 ffff88042dacfd90 0000000000000000 ffffffffa04e2140
[    6.229452] Call Trace:
[    6.229466]  [<ffffffff8176e215>] dump_stack+0x45/0x57
[    6.229469]  [<ffffffff8109bc1a>] warn_slowpath_common+0x8a/0xc0
[    6.229472]  [<ffffffff8109bd4a>] warn_slowpath_null+0x1a/0x20
[    6.229474]  [<ffffffffa04ca401>] v4l_querycap+0x41/0x70 [videodev]
[    6.229477]  [<ffffffffa04ca6cc>] __video_do_ioctl+0x29c/0x320 [videodev]
[    6.229479]  [<ffffffff81227131>] ? do_last+0x2f1/0x1210
[    6.229491]  [<ffffffffa04cc776>] video_usercopy+0x366/0x5d0 [videodev]
[    6.229494]  [<ffffffffa04ca430>] ? v4l_querycap+0x70/0x70 [videodev]
[    6.229497]  [<ffffffffa04cc9f5>] video_ioctl2+0x15/0x20 [videodev]
[    6.229499]  [<ffffffffa04c6794>] v4l2_ioctl+0x164/0x180 [videodev]
[    6.229501]  [<ffffffff8122e298>] do_vfs_ioctl+0x2f8/0x500
[    6.229502]  [<ffffffff8122e521>] SyS_ioctl+0x81/0xa0
[    6.229505]  [<ffffffff81774a09>] system_call_fastpath+0x12/0x17
[    6.229506] ---[ end trace dacd80d4b19277ea ]---

This is the warning about querycap not filling device_caps properly. The tree has dfdf780b4651cf4932b96d3fe296230afacc360a ('[media] cx18: add device_caps support') present already but I noticed several of the streams types are missing capabilities in cx18-streams.c (CX18_ENC_STREAM_TYPE_TS, CX18_ENC_STREAM_TYPE_PCM, CX18_ENC_STREAM_TYPE_IDX)

Do these need to have proper capabilities added as well to silence this warning?

Thanks,
Laura

Hi Laura,

Thanks for the report. I've made a patch and CC-ed you on it. The TS and IDX streams are internal (i.e., they do not map to a V4L2 device node), but the PCM stream isn't, and that's the one causing the warning.

Regards,

Hans