Re: revert dma direct internals abuse

[Thomas Hellstrom]

Hi, Christoph,

On Mon, 2019-04-22 at 19:56 +0200, hch@xxxxxx wrote:
> On Wed, Apr 10, 2019 at 03:01:14PM +0000, Thomas Hellstrom wrote:
> > > So can you please respin a version acceptable to you and submit
> > > it
> > > for 5.1 ASAP?  Otherwise I'll need to move ahead with the simple
> > > revert.
> > 
> > I will. 
> > I need to do some testing to investigate how to best choose between
> > the
> > options, but will have something ready for 5.1.
> 
> I still don't see anything in -rc6..

Been on easter vacation. I have a patch ready for review, though, will
send it out in a moment.

It turns out that to do something well-behaved in case someone sets
swiotlb=force, the variable swiotlb_force would need to be exported.
(I can't rely on swiotlb_nr_tbl()).

That's not currently done in the patch, but instead the driver just
malfunctions like most other graphics drivers.

/Thomas