Re: memory that can be sent to usb control msg

["John Tyner" <jtyner@cs.ucr.edu>]

> The USB core needs memory that is created with kmalloc.  Why would you
> be wanting to send a larger buffer in one shot through the USB core than
> what you can create with kmalloc?
>
> How large of a buffer do you want to try to send at one time?  And why
> can't you split it up into tiny buffers, like the USB device wants?
>
> What kind of USB device is this driver for?

The problem isn't trying to send that much memory. The device is a camera,
and I was trying to allocate and array of frames but only pass one at a time
down. I guess I'll rethink that design. :)

If you (or anyone else has time) can you explain the purpose of the
rvmalloc/rvfree and uvirt_to_kva/kvirt_to_pa functions in the bttv and cpia
drivers do? And is there a generic replacement for these as the comments in
those drivers suggest?

(I'm writing a driver for 2.4 driver at the moment.)

Thanks for the help.
John

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