Denis A. Altoé Falqueto wrote:> I've bought a (el cheapo) midi-usb cable so I can play my musical> keyboard (also el cheapo... but I'm no professional :)). The thing is> that when I try to use it in my laptop (Gigabyte W566U, ArchLinux 64> bits, up to date), it is not reliable. I play the keys and the midi> events are not delivered correctly. I'm using aseqdump to debug. For> example, I press 5 keys and see 5 key down events, but when I releas> them, only 2 o 3 note up events are shown. And if I play too many> notes, it just stops receiving any events from the device, dmesg show> a strange message "urb status -75" and reconnects the usb device. Is there also a message when single events are lost? 75 means EOVERFLOW. linux/Documentation/usb/error-codes.txt says:| -EOVERFLOW (*) The amount of data returned by the endpoint was| greater than either the max packet size of the| endpoint or the remaining buffer size. "Babble".|| (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate| hardware problems such as bad devices (including firmware) or cables. > I tested the same cable on my old desktop (Asus A7N8X-X motherboard,> nvidia MX440 graphics card, 5 years of intensive e loyal use,> ArchLinux 32 bits) and it works fine. The difference between the two> seems to be the usb module that handles the device. [...]> Does anyone has any suggestions on how can I force ohci_hcd to be> loaded before uhci_hcd? Or is it realy the problem? ohci_hcd works only with an OHCI controller; uhci_hcd works only witha UHCI controller. Loading the other one will not have any effect. If you really want to try a different driver, connect the interfacethrough a USB 2.0 hub; this will be handled by ehci_hcd. But I guessthis won't make any difference. What kernel version are you using on each machine? The ICH8M chip of your laptop isn't known for making USB problems.This might be a problem with a USB port (try another one) or thelaptop's wiring. Best regards,Clemens_______________________________________________Linux-audio-user mailing listLinux-audio-user@xxxxxxxxxxxxxxxxxxxxxxxx://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
