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> 75 means EOVERFLOW. linux/Documentation/usb/error-codes.txt says:<br>> | -EOVERFLOW (*) The amount of data returned by the endpoint was<br>> | greater than either the max packet size of the<br>> | endpoint or the remaining buffer size. "Babble".<br><br>Are you running any application on your system or just aseqdump? You<br>might find that if you are running a phat softsynth in realtime mode that<br>it is chewing up chunks of CPU when note events occur and preventing<br>the USB from being serviced?<br><br>You might also want to look at whether your CPU governor is 'ondemand'<br>rather than performance although even having said that, if the CPU had<br>stepped down to just 600MHz as my laptop does, that is still 100M cycles<br>per MIDI event which is more than aseqdump would need. Typically.<br><br>Have you looked at the version of the ALSA drivers? Just to make sure <br>that the drivers are servicing the input buffer correctly, emptying it in a<br>timely fashion.<br><br>Regards, nick.<br><br>"we have to make sure the old choice [Windows] doesn't disappear”.<br>Jim Wong, president of IT products, Acer<br><br><br><br><br>> Date: Thu, 18 Jun 2009 09:57:11 +0200<br>> From: cladisch@fastmail.net<br>> To: linux-audio-user@lists.linuxaudio.org<br>> Subject: Re: [LAU] Problems with usb midi cable<br>> <br>> Denis A. Altoé Falqueto wrote:<br>> > I've bought a (el cheapo) midi-usb cable so I can play my musical<br>> > keyboard (also el cheapo... but I'm no professional :)). The thing is<br>> > that when I try to use it in my laptop (Gigabyte W566U, ArchLinux 64<br>> > bits, up to date), it is not reliable. I play the keys and the midi<br>> > events are not delivered correctly. I'm using aseqdump to debug. For<br>> > example, I press 5 keys and see 5 key down events, but when I releas<br>> > them, only 2 o 3 note up events are shown. And if I play too many<br>> > notes, it just stops receiving any events from the device, dmesg show<br>> > a strange message "urb status -75" and reconnects the usb device.<br>> <br>> Is there also a message when single events are lost?<br>> <br><br>> |<br>> | (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate<br>> | hardware problems such as bad devices (including firmware) or cables.<br>> <br>> > I tested the same cable on my old desktop (Asus A7N8X-X motherboard,<br>> > nvidia MX440 graphics card, 5 years of intensive e loyal use,<br>> > ArchLinux 32 bits) and it works fine. The difference between the two<br>> > seems to be the usb module that handles the device. [...]<br>> > Does anyone has any suggestions on how can I force ohci_hcd to be<br>> > loaded before uhci_hcd? Or is it realy the problem?<br>> <br>> ohci_hcd works only with an OHCI controller; uhci_hcd works only with<br>> a UHCI controller. Loading the other one will not have any effect.<br>> <br>> If you really want to try a different driver, connect the interface<br>> through a USB 2.0 hub; this will be handled by ehci_hcd. But I guess<br>> this won't make any difference.<br>> <br>> What kernel version are you using on each machine?<br>> <br>> The ICH8M chip of your laptop isn't known for making USB problems.<br>> This might be a problem with a USB port (try another one) or the<br>> laptop's wiring.<br>> <br>> <br>> Best regards,<br>> Clemens<br>> _______________________________________________<br>> Linux-audio-user mailing list<br>> Linux-audio-user@lists.linuxaudio.org<br>> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user<br><br /><hr />See all the ways you can stay connected <a href='http://www.microsoft.com/windows/windowslive/default.aspx' target='_new'>to friends and family</a></body>
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