Hm, any reason you took this off of the list?
It should have been on there, my mistake
On Thu, Jul 31, 2003 at 09:43:35AM +0200, Koen Van Renterghem wrote:
> At 14:16 30/07/2003 -0700, you wrote:
> >On Tue, Jul 29, 2003 at 04:03:15PM +0200, Koen Van Renterghem wrote:
> >> Hello,
> >>
> >> I noticed that usb_register_dev() has changed in recent kernels. The
> >'old'
> >> function (2.5.69) could allocate a continious chunk of 16 minors, but the
> >> new version only allocates a single minor. I would like to have several
> >> minors available to my driver, how can this be implemented?
> >
> >You still have many minors available to your driver, just ask for them
> >when your device is connected.
>
> Could you elaborate a bit more on how this should be handled? In the probe
> function I used to allocate 16 minors with usb_register_dev(). I want
> to control a single piece of hardware through that minor range. How do
> I ask for additional minors after calling usb_register_dev() in the
> probe function?
You want more than one minor per USB device? During 2.5, usb_register_dev() could handle that, but no one ever used it that way, so it was changed to only dole out 1 minor at a time per device.
It's a good thing to keep the code as clean as possible, but for me this
limits the possibilities. I can imagine that other developers will run into
similar trouble in the future. Maybe it should be reconsidered to allow
allocation of a block of minors, I don't think that it adds a lot of complexity
to the code.
I also consider it a good thing to keep the API as versatile as possible,
but thats just one persons opinion of course.
If you want your driver to go into the main kernel tree, I can reconsider changing the function back.
Since I'am working on something that only exists in the lab as a first prototype there
is no point in including it in the main kernel tree right now I guess.
> > What driver are you writing, and have > >you reserved a minor number range for it? > > No I don't, but this isn't a real problem since I'am working on custom > hardware based on the Cypress FX2. Everything is currently in the > research phase.
Any reason why you have to write a kernel driver and can't do everything from libusb/usbfs?
I'am working on something that can log data very fast. With 2.5.59 I was able to transfer 40Mb/s sustained
from the cypress FX2, over usb, to harddisk. Using libusb or usbfs would introduce unwanted latency,
and I really need to eliminate all possible overhead.
thanks,
greg k-h
Thanks for your reply, I really appreciate it, Koen
___________________________________________________________________________ ir. Koen Van Renterghem Ghent University Department of Information technology / INTEC-design Sint-Pietersnieuwstraat 41 B-9000 GENT Belgium, Europe ___________________________________________________________________________
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