Hello again Clemens. > Il 22 marzo 2019 alle 15.06 Clemens Ladisch <clemens@xxxxxxxxxx> ha scritto: > > > Guido Trentalancia wrote: > > Also, the hardware is the same: Hercules P32 DJ (with exactly the same > > firmware version 1.46 which is the latest). > > Are the USB controllers the same (2.0/3.x, OHCI/UHCI/EHCI/xHCI)? > > You wrote that "amidi -p hw:2,0,0 -d" causes the problem. As long as no > MIDI messages are actually received, the kernel or driver cannot affect > what happens on the USB bus; the polling is done entirely by the host > controller. I have double-checked this too and I can now confirm: "amidi -p hw:2,0,0 -d" does not increase the RX/TX (I/O) bytes count in /proc/asound/card2/midi0. So, what kind of operation does amidi trigger in the kernel which causes the problem ? What does it actually do ? I saw you wrote the ALSA USB MIDI driver (sound/usb/midi.c). But the MIDI seems to run fine, I can receive (RX) data from the controller fine. It is the audio part (card.c, pcm.c, clock.c and so on) that is being disturbed by simultaneous MIDI operation ! What do you say ? > Regards, > Clemens _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
