Khadas VIM2 and DTV board

    There is no data stream from demodulator. Demodulator can be connected for parallel (GPIODV_0 - GPIODV_7) or serial (GPIODV_0) data transfer.

    K-series boxes and WP2 use parallel and VIM2 use serial. Kind of data transfer for kernel modules (aml_dmx) is set via dtb. But driver is hard coded for parallel transfer. For future investigating and testing without physical HW is for me impossible.

    Quote from afl1

    There is no data stream from demodulator. Demodulator can be connected for parallel (GPIODV_0 - GPIODV_7) or serial (GPIODV_0) data transfer.

    K-series boxes and WP2 use parallel and VIM2 use serial. Kind of data transfer for kernel modules (aml_dmx) is set via dtb. But driver is hard coded for parallel transfer. For future investigating and testing without physical HW is for me impossible.

    Do you mean that driver doesn't have capability to manage serial data transfer or, is it a problem of pin assignments? Is the last DTB you have sent correct?

    What about this patch? (it solved the problem with the Android kernel version) Could be it applied to the S912 project?

    Quote from caligari

    Do you mean that driver doesn't have capability to manage serial data transfer or, is it a problem of pin assignments? Is the last DTB you have sent correct?

    What about this patch? (it solved the problem with the Android kernel version) Could be it applied to the S912 project?

    afl1 did you read the previous post? In Khadas forum they can provide you free physical samples, it has been commented here: DVB/DTV Extension Board for VIM2 (VTV) - Hardware and Peripherals - Khadas Community

    We need to unlock this issue asap, as there are many people waiting for a fix.

    Regards.

    Quote from Shoog

    I have an unrelated question regarding the dTV board which maybe best asked here or in a separate thread.

    For me its fairly important that I can get the SPIDF on the dTV board to output without the TV been on. What seems to be happening is that the SPIDF on the dTV board is tied to the HDMI output such that when the TV is off the SPIDF on the board stops working. There is no option in the audio settings to select the dTV board SPIDF.

    So is it likely that this is a driver issue or is it a Libreelec settings issue ?

    Shoog

    sounds like a bootloader issue, maybe try turning off hdmi-cec

    Quote from adamg

    sounds like a bootloader issue, maybe try turning off hdmi-cec

    Tried messing about with the CEC settings and disabling CEC but nothing helped.

    I think its a HDMI handshaking issue coupled to Amlogic taking shortcuts with the drivers. They basically piggybacked the SPIDF output onto the HDMI output and haven't offered it as a seperate ALSA card.

    Shoog

    Quote from Shoog

    Tried messing about with the CEC settings and disabling CEC but nothing helped.

    I think its a HDMI handshaking issue coupled to Amlogic taking shortcuts with the drivers. They basically piggybacked the SPIDF output onto the HDMI output and haven't offered it as a seperate ALSA card.

    Shoog


    I remember kszaq talking of a use case when I was trying to submit a pull request to LE where by a user may want to play audio with no hdmi connected and use Kore to control Kodi, I assume you are trying to do something similar here. The spdif stays active with chinese S905 boxes when no HDMI is connected so the same should happen here.

    Quote from adamg


    I remember kszaq talking of a use case when I was trying to submit a pull request to LE where by a user may want to play audio with no hdmi connected and use Kore to control Kodi, I assume you are trying to do something similar here. The spdif stays active with chinese S905 boxes when no HDMI is connected so the same should happen here.

    It seems that this is a combination of compounded problems traceable back to dubious decisions made by the Kodi team to disable passthrough in certain situations due to sync issues. This effected the driver within Libreelec which dropped support for a seperate SPIDF feed. I checked that this wasn't just an issue with the Libreelec settings by running aplay -L which has the same ALSA cards as Libreelec shows. The driver fudge seems to be that SPIDF was simply slaved to the HDMI output and responds to the same handshaking signals as the TV, and no SPIDF card exists.

    It seems that its a common problem to all the s912 boxes.

    Its not an Amlogic hardware issue.

    This is an ALSA driver issue so it could be solved with a re-write of the sound drivers, but since this has been hanging for a while now its unlikely to get solved any time soon.

    So my use case is that we use my box for Radio listening and it offends me that I have to have the TV on to do so (burning 200W+ of power to drive a visualization). Its not a deal breaker but is very annoying. Rolling back to Jarvis would probably solve it, but then the prospect of getting the sat support working recedes into never never land.

    So I am thinking, would an audio signal splitter resolve the issue. I cannot get from the specs whether the splitter boxes take over handshake duties or whether the TV is still master when it comes to telling the Kodi box whether there is a TV present.

    Shoog

    if what you say is true then you would need a device capable of identifying itself and sending edid data etc...

    I would say sat support is never never land either I believe khadas team are or will be providing afl1 with the board and I suspect he will resolve the issue very quickly once he does get it.

    It's very hard to do testing remotely, make 1 change and wait for user to test and trust the users are testing properly before saying it doesn't work, it's the exact reason I didn't want to do an s912 build before I could personally test it.

    I have every confidence that afl1 will resolve the SAT card issue within days of getting the board (however long it takes to ship is another matter).

    However I can't see this SPIDF issue ever getting resolved since its a classic corner case. Since the SAT will only work on the latest builds a roll back is out of the question. I am stuffed !

    Read this thread for a detailed explanation of whats going on:
    passthrough output device grayed out

    Shoog

    Edited once, last by Shoog (January 28, 2018 at 10:51 AM).

    I just discovered that I made a mistake regarding the SPIDF issue. I had my amp set to the analogue output from the TV and not my SPIDF driven DAC. I can now correct myself and say that the SPIDF stays alive when the TV is off.

    I apologise for the confusion and request that these comments be deleted as misleading.

    Shoog

    Quote from Shoog

    I just discovered that I made a mistake regarding the SPIDF issue. I had my amp set to the analogue output from the TV and not my SPIDF driven DAC. I can now correct myself and say that the SPIDF stays alive when the TV is off.

    I apologise for the confusion and request that these comments be deleted as misleading.

    Shoog

    Glad to hear you sorted it, I did find it strange when you first mentioned the issue because Chinese boxed have always been capable of this

    Status update:

    Quote

    Finally this week arrived VIM2 + VTV.

    I started work to adopt AVL6862 driver to support VTV board.

    Current driver support Mecool K-series devices. The main differences between Mecool and Khadas is how is AVL6862 demodulator connected to S912 hw demuxer. Mecool use parallel connection (8 bits) vs. Khadas serial.

    Current open source AVL6862 driver by Luis Alves supports only parallel transfer.

    Task to do:

    1. Modify device tree blob to serial connection and support lock led;
    2. Add serial support to AVL6862 driver;
    3. Update amlogic modules aml_dvb and aml_dmx to accept serial data from demodulator
      Work is in progress. The first two step are almost done.
      Currently I am very busy and I have no spare time to concentrate on 3. point

    Very close now I think !!

    Quote

    Today I tested first working build.

    Work progress:

    1. serial2parallel conversion in S912 is working;
    2. driver is now able scan channels, I tested it for dvb-s and dvb-t;
    3. blue channel lock led is fixed;
    4. live tv playback is working only for few channels, I have to fixed this issue.