[alsa-devel] USB transfer_buffer allocations on 64bit systems

Daniel Mack daniel at caiaq.de
Thu Apr 8 13:07:43 CEST 2010

On Thu, Apr 08, 2010 at 08:09:11AM +0200, Oliver Neukum wrote:
> Am Mittwoch, 7. April 2010 17:35:51 schrieb Daniel Mack:
> > > Alan, any objection to just using usb_buffer_alloc() for every driver?
> > > Or is that too much overhead?
> > 
> > FWIW, most drivers I've seen in the past hours use a wild mix of
> > kmalloc(), kzalloc(), kcalloc() and usb_buffer_alloc(). That should
> > really be unified.
> kmalloc() & friends != usb_buffer_alloc(). They do different things.

I know. I just believe that many developers used usb_buffer_alloc() even
though they don't really need coherent DMA memory. The function's name
is misleading, and copy'n paste does the rest.

> It makes no sense to unify them. If you really need an ordinary
> buffer DMA will surely work on, this needs a third primitive.

I think it will help a lot to rename usb_buffer_alloc() in the first
place and then reconsider where coherent memory is really needed.


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