[alsa-devel] Hercules P32 DJ: severe sound distortion during MIDI transfers

[Guido Trentalancia]

# cat /sys/bus/usb/devices/usb[12]/version 
 2.00
 2.00

# cat /sys/bus/usb/devices/usb[12]/product 
EHCI Host Controller
EHCI Host Controller

# cat /sys/bus/usb/devices/usb[12]/manufacturer 
Linux 5.0.2 ehci_hcd
Linux 5.0.2 ehci_hcd

# cat /sys/bus/usb/devices/usb[12]/speed 
480
480

What other information do you need ?

Do you suggest some particular USB module configuration to try ?

Regards,

Guido

> Il 22 marzo 2019 alle 15.06 Clemens Ladisch <clemens at ladisch.de> 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.
> 
> 
> Regards,
> Clemens