Re: sdio: enhance IO_RW_EXTENDED support

[Pierre Ossman]

On Mon, 06 Aug 2007 11:31:19 +0100
David Vrabel <david.vrabel@xxxxxxx> wrote:

> 
> I would expect the block size to be set once per card, and never be
> changed and thus it's not logically a per-transfer operation.  We
> certainly wouldn't want to change the block size willy-nilly as it's
> an expensive operation.
> 

Indeed. It would of course be optimized so that it doesn't change the
size needlessly.

The beauty is that drivers wouldn't have to care. Things just
work<tm>. :)

> > I suspect that some transactions might require a certain block size.
> > But we could satisfy that by stating that any transfer small enough
> > to fit into one block will not be split up.
> 
> I consider it unlikely that any card would want to do anything other
> than always use the largest possible block size.
> 

I have a counter example. I have here a Marvell wifi card which needs a
firmware upload. And it seems to be rather picky about parameters
during that upload.

I'm still experimenting with a clean way to do things for this card.
I'll get back to you. :)

Rgds
-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  PulseAudio, core developer          http://pulseaudio.org
  rdesktop, core developer          http://www.rdesktop.org
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