DVB issue since LE switched to kernel 4.9.x

  • Part of the fix for upstream Kernel is to add vchiq DT data:

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    That makes it to create /dev/vchiq devnode.

    With that, kodi doesn't crash anymore, but those messages are generated:

    Code
    [    6.846340] vchiq: module is from the staging directory, the quality is unknown, you have been warned.
    [    6.851573] vchiq: vchiq_init_state: slot_zero = ea880000, is_master = 0
    [    7.027647] [<bf00c794>] vchiq_doorbell_irq [vchiq]
    [    8.022814] Modules linked in: cfg80211(+) vc4(+) snd_soc_core ac97_bus snd_pcm_dmaengine snd_pcm snd_timer snd crc32_arm_ce brcmutil soundcore vchiq(C)
    [  106.220212] vchiq: vchiq: connect: could not lock mutex for state 0: -4
    [  149.432097] vchiq: vchiq: could not connect: 1

    Maybe vchiq DT data changed since Kernel 4.11 (the last time I used my RPi3).

    @mcmehab I'm sorry it's taken so long to get to the bottom of this problem, but fortunately the solution turns out to be simple.

    Your patch to the .dtsi file above is correct (ignoring the bogus size of 0xf which all VCHIQ nodes use) except for one important difference - you have placed the vchiq node in the root of the tree instead of as a child of the /soc node. This isn't just a cosmetic issue - by being outside /soc, vchiq fails to inherit some important properties, including "ranges" which describes how to map kernel physical addresses onto bus addresses and vice-versa, preventing the driver from accessing the doorbell registers.

    If you move your addition up a few lines so that it is inside /soc then the address mapping magic will work and vchiq will spring into life.

    Edited once, last by pelwell (January 23, 2018 at 11:03 AM).

  • Have you enabled hardware acceleration (VDPAU in your case) in settings>system>display?

    My graphics card is also NVidia ION-based, and my machine cannot cope unless i turn on the h/w acceleration.

    Also, is your cpu overloaded when playing back the stream? As this would be another indicator that the stream is not being decoded by your gpu.

    Hi jahutchi, thanks for the reply.

    I don't seem to have that setting (expert mode is enabled), but the codec info window during playback shows that HW decoding is active . No spikes in CPU - sits at around 5-10%.

    most likely the driver has problems, not sure how to fix it - maybe try Releases · sammy2142/LibreELEC.tv · GitHub with older drivers if they work (idk if your GPU is already legacy or not)

    Hi & thanks CvH... I'll give sammy's build a whirl and report back.

  • most likely the driver has problems, not sure how to fix it - maybe try Releases · sammy2142/LibreELEC.tv · GitHub with older drivers if they work (idk if your GPU is already legacy or not)

    Hi CvH, I installed sammy's build with the legacy nvidia drivers. Still get the artifacts - in exactly the same place for the recorded F1 clip. Live TV has them too.

    This issue definitely came about since LE8. I was using your community 7 builds w/ TBS drivers - had no problems with artifacts there...

    Any ideas anyone ?

  • Hi CvH, I installed sammy's build with the legacy nvidia drivers. Still get the artifacts - in exactly the same place for the recorded F1 clip. Live TV has them too.

    This issue definitely came about since LE8. I was using your community 7 builds w/ TBS drivers - had no problems with artifacts there...

    Any ideas anyone ?

    This sounds exactly like my problem. But I have an AMD E350.

  • as long the recordings are okay and play okay at VLC ... this is no DVB driver problem

    pls open a new thread about it with attached kodi logs :)

    I also did a recording and I have the issue also in my recording played with VLC. So maybe DVB related? I have video and audio glitches.

  • as long the recordings are okay and play okay at VLC ... this is no DVB driver problem

    pls open a new thread about it with attached kodi logs :)

    Thanks CvH - opened a new thread here:

    I also did a recording and I have the issue also in my recording played with VLC. So maybe DVB related? I have video and audio glitches.

    Is your VLC on a different machine? Live TV and recordings play back fine on a AMD A4 APU laptop for me.

    NB i have no audio glitches. Just black artefacts.

    Also might be worth jumping on the my other thread and add your logs perhaps ?


    Neil

  • Hi, i changed now from milhouse#0110b to 8.2.3. and got again dataerros. Not as much as with 8.2.2. but still more as with the latest milhousebilds....there i had 0 for aboud 2hour....with 8.2.3

    About 200....any idea why????

  • Dear LibreElec-Users

    I've stumbled upon this thread upon trying to find out, whats causing artefacts and slow-channel-switching when watching live TV.

    My setup: Raspberry Pi 3 running LibreELEC 8.2.2 (installed with PINN, parallel to RetroPie and Raspbian), TVHeadend 4.2 with a MyGica/Geniatech T230 over the DVB-C tuner.

    The channel switching is really really slow most of the time, I got artefacts on all HD channels (h.264) and when trying to tune in Radio-Channels, the RPi3 reboots after one second of playback all the time.

    I am unfortunately a newbie to RPIs/Linux, therefore I do not know, how to use the here posted fixes/reverts and would gladly appreciate some help or someone "pointing me" in the right direction.

    Thanks! :)

  • Unfortunately, I still have problems with LE 8.2.3. I moved to a new place this weekend, its the same DVB-C provider, according to TVHeadend adapter status, the connection seems even better than at my old place (-50 at the old place, around -30 at the new place), but I get even more artefacts, slow channel switching, etc.

    Anyone have any idea what I could try to do?

    Thanks :)