December 22, 2025Dec 22 Please help. We bought a board on AliExpress, but no one provided any documentation. And I can't ask the seller for it. Can anyone share any information? It's very difficult to figure out which pin goes where without documentation on the circuit diagrams. But given my situation, I set up two Ethernet interfaces. I haven't tested them at full capacity, but I can ping from both networks... myd lt527m 16e2d 180 e sx Thanks a lot. Edited December 22, 2025Dec 22 by xaba55 дополнение
December 22, 2025Dec 22 moved. Has nothing to do with opi4a. Remove heatsink to get an idea which SoC hides beneath
December 27, 2025Dec 27 Author This is a MYD-lt527m-16e2d-180-e-sx board. Allwinner T527 chip. The seller isn't helping. It's hard to figure out how the peripherals are connected.
December 27, 2025Dec 27 Without schematics, deep knowledgde and a lot of time to waste, this task is probably close to impossible. Only chance I see here is for once assuming the vendor is lazy and the implementation is as close to reference design as it can get. And for the other that there is some android device tree which can be reverse-engineered.
December 27, 2025Dec 27 Author Thanks. Regarding Android, it seems to be the most optimal. But I was still hoping someone would have a schematic
December 27, 2025Dec 27 Have you tried to reach out to the manufactur? https://www.mouser.at/datasheet/3/2627/1/MYD-LT527-SX.pdf Website: en.myir.cn Email: sales@myir.cn Tel: +86-755-22984836
December 27, 2025Dec 27 Author I reread it, but the information is not publicly available. Contact them directly? I haven't tried. Maybe they can help. Thanks for your time. I'll write back later; maybe someone will be interested. Edited December 27, 2025Dec 27 by xaba55
January 3Jan 3 Author Good afternoon. Sorry for my English. Happy New Year!!!! Can you change the current theme to MYD-lt527m-16e2d-180-e-sx? I think that's clear now. Thank you. By the way, I've made some progress. Using Android logs, I finally configured, launched, and tested two network interfaces. The iperf3 program showed an average throughput of 90 megabytes per second. Unfortunately, I can't yet extract the device tree using standard tools. Edited January 3Jan 3 by xaba55
January 7Jan 7 Author I managed to get a device tree from Android. The veil has been lifted))) android-dtbo_MYD-lt527m-16e2d-180-e-sx.dts
January 8Jan 8 Author I'm trying to start sound. The device is created, but the error is "Write error: -5,Input/output error." The logs show the entry [ 7.411495] sun6i-dma 7121000.dma-controller: private_candidate: dma1chan0 busy [ 20.743313] sun6i-dma 7121000.dma-controller: private_candidate: dma1chan0 busy [ 20.743325] sun6i-dma 7121000.dma-controller: private_candidate: dma1chan1 busy [ 20.743391] sun6i-dma 7121000.dma-controller: private_candidate: dma1chan0 busy [ 20.743400] sun6i-dma 7121000.dma-controller: private_candidate: dma1chan1 busy [ 20.743409] sun6i-dma 7121000.dma-controller: private_candidate: dma1chan2 busy Why is it busy? # speaker-test -Dhw:2 -r48000 -c2 -tsine -f1000 speaker-test 1.2.14 Playback device is hw:2 Stream parameters are 48000Hz, S16_LE, 2 channels Sine wave rate is 1000.0000Hz Rate set to 48000Hz (requested 48000Hz) Buffer size range from 32 to 131072 Period size ra[ 194.914904] sun6i-dma 7121000.dma-controller: vchan 0000000060790fd8: txd 00000000925572c7[2]: submitted [194.914931] dma dma1chan2: vchan 0000000060790fd8: issued [ 194.914968] sun6i-dma 7121000.dma-controller: pchan 0: alloc vchan 0000000060790fd8 [194.914980] dma dma1chan2: [ 194.914980] desc: p - 0x00000000a9840060 v - 0x00000000be392dcf [ 194.914980] c - 0x03820481 s - 0xa9a00000 d - 0x07116020 [ 194.914980] l - 0x0000bb80 p - 0x00000008 n - 0xa9840040 [ 194.914998] sun6i-dma 7121000.dma-controller: Common register: [ 194.914998] mask0(0000): 0x00000002 [ 194.914998] mask1(0004): 0x00000000 [ 194.914998] pend0(0010): 0x00000000 [ 194.914998] pend1(0014): 0x00000000 [ 194.914998] stats(0030): 0x00000001 [194.915015] sun6i-dma 7121000.dma-controller: Chan 0 reg: [ 194.915015] ___en(0000): 0x00000001 [ 194.915015] pause(0004): 0x00000000 [ 194.915015] start(0008): 0xa9840060 [ 194.915015] __cfg(000c): 0x00000000 [ 194.915015] __src(0010): 0x00000000 [ 194.915015] __dst(0014): 0x00000000 [194.915015] count(0018): 0x00000000 [ 194.915015] _para(001c): 0x00000000 [194.915015] nge from 16 to 65536 Periods = 4 was set period_size = 12000 was set buffer_size = 48000 0 - Front Left Write error: -5,Input/output error xrun_recovery failed: -5,Input/output error Transfer failed: Input/output error Edited January 8Jan 8 by xaba55
January 9Jan 9 Author This isn't a DMA problem. There are too many inconsistencies in the audio driver. The driver needs to be fixed first.
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