Soundbytes Posted October 26, 2015 Posted October 26, 2015 Hi there, I have now finally managed to apply the RT Kernel patch on the Bananapi. (Original Patch here: https://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patch-3.4.108-rt136.patch.gz) The patch did not work out of the box and I had a bit of hassle to fix all of the rejected bits. To me the Banana Pi is best suited for audio production since it is very affoedable and it already comes with a usable audio out. To get the full benefit of the RT kernel patch it was necessary to thrn also reduce the buffer size of the inbuilt sunxi -codec audio driver. I can now play a synth using a buffer size of 512 samples glitch free. Here are some numbers: ansum@bananapi:~$ cat /proc/asound/card0/pcm0p/sub0/hw_params access: RW_INTERLEAVED format: S16_LE subformat: STD channels: 2 rate: 44100 (44100/1) period_size: 128 buffer_size: 512 ansum@bananapi:~$ top top - 14:59:12 up 1:20, 3 users, load average: 0.35, 0.25, 0.18 Tasks: 108 total, 1 running, 107 sleeping, 0 stopped, 0 zombie %Cpu(s): 7.1 us, 7.5 sy, 0.0 ni, 85.4 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st KiB Mem: 734420 total, 229800 used, 504620 free, 10416 buffers KiB Swap: 131068 total, 0 used, 131068 free. 168728 cached Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 946 ansum 20 0 32116 2328 1584 S 18.0 0.3 5:23.36 stk-demo 3 root -2 0 0 0 0 S 3.9 0.0 2:04.22 ksoftirqd/0 11 root -2 0 0 0 0 S 3.6 0.0 2:34.05 ksoftirqd/1 16 root -51 0 0 0 0 S 2.3 0.0 1:13.79 irq/59-dma_irq 71 root -51 0 0 0 0 S 2.0 0.0 0:04.19 irq/71-ehci_hcd 1207 ansum 20 0 4540 1204 840 R 1.3 0.2 0:00.46 top Until now I have only tested with a relatively lightweight monophonic synth. It remains to be seen how good the system performs under heavier load. And yes: I did not install the desktop to save precious CPU cycles. If anybody is interested - I have attached the patches. It is just a few file additions and replacements within Igors build system. Make sure you have built a clean armbian image at least once before you go on and apply the patches. Disclaimer: This is untested software and I have no Idea what it will do to your Bananapi if you decide to give it a try. Edit: It looks like am not allowed to upload attachments. Please download from here: http://soundbytes.de/patches/armbian_BaPiRT.tar.bz2 Andreas
Igor Posted November 1, 2015 Posted November 1, 2015 Thanks!I added the patch to the build script. If anyone want's to use it - at this point you need to uncomment it in "patching.sh" until I fix this better way. https://github.com/igorpecovnik/lib/blob/second/patching.sh#L223
Jean-Philippe Theroux Posted October 14, 2016 Posted October 14, 2016 hello im trying to add midi support into loboris' kernel can anyone help me? or lead me into success? =)
Jean-Philippe Theroux Posted October 14, 2016 Posted October 14, 2016 i see that you guys are actually supporting this...
Igor Posted October 14, 2016 Posted October 14, 2016 Yes we do, but only our own kernel, not 3rd party. This is hard enough to support. http://docs.armbian.com/Developer-Guide_Build-Preparation/
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