Hi all, I'm working on a realtime audio application running on a rk3288 platform. The application is written in the JUCE framework, and uses ALSA for audio output. I build the application in a debian jessie chroot since it needs a bunch of libraries compiled for armhf. The application used to run fine on 4.8 mainline, without noticable audio dropouts. I had to upgrade recently to 4.10 mainline to get the audio gadget driver working, but now the application has audio dropouts (pause in the audio output). I have been using 44100 hz sample rate and 960 samples buffer size for testing. I increased the buffer size to 1280 which seemed to improve things a little, and then after googling around I changed the IO scheduler to noop (it was set to CFQ), which further increases the performance. I now only have occasional audio dropouts. The application does a lot of I/O via HID and has 4 audio processing threads for signal processing, besides other threads and callbacks for HID I/O. Questions: 1) Does anyone know if something has changed between kernel 4.8 and 4.10 with regard to the scheduler that might negatively impact realtime audio or RT performance in general? 2) are there specific kernel settings I should check? 3) I am wondering if RT patches are still relevant for newer kernels like 4.8 and 4.10? 4) I saw that the latest patches are for kernel 4.4, can they be applied to later kernels and is that a good idea or not? Thanks for helping! Bert -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
