Re: USB transfer_buffer allocations on 64bit systems

[Greg KH <greg@kroah.com>]

On Wed, Apr 07, 2010 at 05:35:51PM +0200, Daniel Mack wrote:
> On Wed, Apr 07, 2010 at 08:31:54AM -0700, Greg KH wrote:
> > On Wed, Apr 07, 2010 at 05:11:25PM +0200, Daniel Mack wrote:
> > > I vote for a clean solution, a fixup of existing implementations and
> > > a clear note about how to allocate buffers for USB drivers. I believe
> > > faulty allocations of this kind can explain quite a lot of problems on
> > > x86_64 machines.
> > 
> > Yeah, I really don't want to have to change every driver in different
> > ways just depending on if someone thinks it is going to need to run on
> > this wierd hardware.
> > 
> > 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.

Yes, if it is necessary that we have to handle this type of crappy
hardware, then it all needs to be unified.  Or at least unified into 2
types of calls, one that needs the bounce buffer fun (what
usb_buffer_alloc() does today), and one that doesn't (usb_kzalloc()
perhaps?)

thanks,

greg k-h