18 Jun
2009
18 Jun
'09
7 a.m.
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".
Are you running any application on your system or just aseqdump? You
might find that if you are running a phat softsynth in realtime mode that
it is chewing up chunks of CPU when note events occur and preventing
the USB from being serviced?
You might also want to look at whether your CPU governor is 'ondemand'
rather than performance although even having said that, if the CPU had
stepped down to just 600MHz as my laptop does, that is still 100M cycles
per MIDI event which is more than aseqdump would need. Typically.
Have you looked at the version of the ALSA drivers? Just to make sure
that the drivers are servicing the input buffer correctly, emptying it in a
timely fashion.
Regards, nick.
"we have to make sure the old choice [Windows] doesn't disappear”.
Jim Wong, president of IT products, Acer
Date: Thu, 18 Jun 2009 09:57:11 +0200
From: cladisch(a)fastmail.net
To: linux-audio-user(a)lists.linuxaudio.org
Subject: Re: [LAU] Problems with usb midi cable
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?
|
| (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate
| hardware problems such as bad devices (including firmware) or cables.
_________________________________________________________________
Show them the way! Add maps and directions to your party invites.
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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 with
a UHCI controller. Loading the other one will not have any effect.
If you really want to try a different driver, connect the interface
through a USB 2.0 hub; this will be handled by ehci_hcd. But I guess
this 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 the
laptop's wiring.
Best regards,
Clemens
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