Re: [linux-audio-dev] USB-MIDI Transfer rate

On Wed, 2005-09-21 at 18:31 +0200, Jens M Andreasen wrote:
> On Wed, 2005-09-21 at 09:54 +0200, Clemens Ladisch wrote:
>
> > It seems the usb-midi driver grabbed the device first. Disable it in
> > the kernel configuration, or put the line
> >
> > usb-midi
> >
> > into the /etc/hotplug/blacklist file.
> >
>
> Thankyou!
>
> Now to get back to the subject. By changing
>
> ep->max_transfer = usb_maxpacket(umidi->chip->dev, pipe, 1);
>
> in the snd_usbmidi_out_endpoint_create function in usbmidi.c to:
>
> ep->max_transfer = 512;
>
> .. I get a 16 fold increase in thruput.
>
> Test data was a SysEx dump for upgrading the firmware which used take
> ~25 sec, now ~1.6 sec. The cute little LCD progress animation isn't
> really visible anymore, but the update appears to be intact.
>
>
>
> mvh // Jens M Andreasen
>
> >
> > HTH
> > Clemens
> >

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