Minix U9-H freeze on kodi loading page / black screen

  • I have a hunch this is a power problem, but figuring it out might be a challenge. When you start Kodi the GPU is used for the first time which increases power demand on the system. The current assumption is that the box follows the Q200 reference design (the legacy device-tree suggests this: https://github.com/LibreELEC/devi…inix_neo_u9.dts) but there are probably differenes. I do have the schematics for the box, but I'm not the greatest reader of them.

    FWIW CoreElec 9.2.8 which I run currently claims to use dt-id: gxm_q200_2g_minix_neo_u9 which I would assume is the same device tree LE is using. I have checked the power supply, it gives 5V, looks solid. My hunch about overclocking might as well be undervolting though. I tried looking into any hint from comparing dmesg outputs from LE and CE, but these differ so much that I am clueless.

    The last thing I wonder if might be an issue is the SD card and its potential incompatibility with the Minix. For LE I am using a different SD card (32GB Samsung) from the one I am using with CE (16GB Transcend).

  • Amlogic mmc controller issues normally exhibit with high-speed card modes and faster speeds and the current/upstream U9-H device-tree is already defeatured to run at a minimum level. The usual way to rule out those issues with modern cards (that have fancy modes and such) is to test with an old, slow, low-capacity card. I have some 2GB cards which aren't much use for an install but are reliable for that kind of testing. Most vendor firmware will power-up the USB section in u-boot automatically which will make the AMLGX boot media discoverable and useable there too, so perhaps try with a USB stick instead of SD card.

    NB: For power-issues I'm thinking the device-tree description of how things are connected (which influences driver probing and power sequencing) might be off; not that the PSU itself is bad (although that would also cause problems). The vendor kernel has drivers for a Minix MCU chip which is not supported upstream; the MCU does handle some power things, but it's mostly low-level and the essentials are configured by u-boot so Linux shouldn't really need to care.

  • Amlogic mmc controller issues normally exhibit with high-speed card modes and faster speeds and the current/upstream U9-H device-tree is already defeatured to run at a minimum level. The usual way to rule out those issues with modern cards (that have fancy modes and such) is to test with an old, slow, low-capacity card. I have some 2GB cards which aren't much use for an install but are reliable for that kind of testing. Most vendor firmware will power-up the USB section in u-boot automatically which will make the AMLGX boot media discoverable and useable there too, so perhaps try with a USB stick instead of SD card.

    I got my hands on another Minix Neo U9-H, and run it with your latest test build and observed the same behavior. It booted alright in textmode and then got stuck with a lot filesystem errors when I started kodi.

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    Which at least ruled out that my original box had some hardware/power supply problem.

    Then I tried to boot from a quite old USB stick instead (8GB SLC rarity) and it booted fine and run kodi fine. So the culprit is the Samsung SD card: https://www.samsung.com/us/computing/memory-storage/memory-cards/pro-endurance-adapter-microsdxc-32gb-mb-mj32ka-am/

    I wonder how to figure out which cards/USB sticks are fine.

  • Purely for kicks can you update to the latest https://chewitt.libreelec.tv/testing/LibreE…h64-11.80.0.tar and share a new dmesg log please. I've described all SD card modes in device-tree and increased the max SD card speed. On most hardware i'd expect this to cause problems, but I'm curious to see what impact/influence it has (not sure it can make things worse).

    The latest build from today seems to work fine with Samsung SD card (I flashed the image anew, to avoid risking having corrupted fs from the previous run). Here is the dmesg:

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    There is actually nothing particular about kodi start in the log. Only, after starting kodi I have connected Air Mouse which is registered at the end of dmesg.

  • since i have no access to linux system i was confused as there was no image to burn but folders

    Not sure exactly what the problem is, but you should be able to just use the LibreELEC SD creator again with the new image and select the card that currently has the previous version on it. It will just overwrite whatever is on the card. If it doesn't show up or shows up as multiple devices or whatever, you can use Disk Management in Windows to remove the partitions on the card. Then it should work.

  • Not sure exactly what the problem is, but you should be able to just use the LibreELEC SD creator again with the new image and select the card that currently has the previous version on it. It will just overwrite whatever is on the card. If it doesn't show up or shows up as multiple devices or whatever, you can use Disk Management in Windows to remove the partitions on the card. Then it should work.

    that's the thing, for osme reason i can't burn it i have to select all files for the burner to see it and afterwards it just isn't read anywhere..disk management says its a RAW partition after i burn the latest file?

    Edited once, last by wapvi (January 5, 2024 at 12:46 PM).

  • Code
    cd /storage/.update
    wget https://chewitt.libreelec.tv/testing/LibreELEC-AMLGX.aarch64-11.80.0.tar
    reboot

    No need to burn/write anything .. Just update the existing installation ^

  • Code
    cd /storage/.update
    wget https://chewitt.libreelec.tv/testing/LibreELEC-AMLGX.aarch64-11.80.0.tar
    reboot

    No need to burn/write anything .. Just update the existing installation ^

    i ended up going the USB route but i'll try again with the sd card

    Edited once, last by wapvi (January 5, 2024 at 7:50 PM).

  • risa2000 Interesting. Nice to see the errors are gone. The log also shows Broadcom WiFi is now missing but I suspect that's due to another change I made. Can you update to https://chewitt.libreelec.tv/testing/LibreE…h64-11.80.0.tar and share the boot log to confirm (it should be fixed if I'm right)?

    I noticed wifi was missing, was thinking it was because I had already wired connection :). The new build fixes that. Here is dmesg log, there are some video errors at the end, but I am not sure if they are relevant (I observed some instability when watching TV or TV recordings from TVHeadend backend).

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    I also noticed that in this build kodi run correctly 1920x1200p@60Hz.

  • I've noticed some glitches playing things back but I haven't had time to investigate properly. I have a hunch this is related to Kodi rendering and not the codecs; though those definitely have their own issues too and that's what shows in the system log. Over time the surrounding kernel keeps moving forwards so the lack of codec maintenance means differences start to creep in, causing minor regressions until eventually something more fundamental breaks. There's an issue with buffers not being free'd which will cause the device to run out of memory over time, and there are other things too.

    The other hardware device that isn't working correctly is the rtc chip, which doesn't report any time data. If the boxes use a coin cell batter that can be removed, remove it and it might show different log messages. If it's a soldered one that's not possible but the thought it that low/under voltage might results in bad or no values being readable.

    Thanks for confirming WiFi works again.

  • for some reason 11.04 doesnt regonise my TV as a 4K tv its rendering the GUI at some weird resolution with a max of 800 of width using the same hdmi i have used for my series X..and playback is borked as theres no HDR and everything is washed out..

  • Kernel DRM doesn't see valid EDID data for the TV and falls back to some default resolutions. Kodi then configures itself based on what the kernel says the TV can do. I'd check/replace cables or change the socket the box is connected to. NB: The same image is showing everything fine here (on a VIM1, but that's irrelevant).