Re: [PATCH 34/49] gma500: the GEM and GTT code is deviceindependant

[Alan Cox]

On Tue, 18 Oct 2011 06:59:28 -0500
Rob Clark <rob.clark@xxxxxxxxxx> wrote:

> On Tue, Oct 18, 2011 at 5:45 AM, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
> >> What troubles could you see for swap+uncached (or more likely,
> >> writecombine) pages?
> >
> > That should never occur. I would argue the driver is responsible for
> > putting the cache state of the page back sensibly before it unpins it.
> > That's a simple enough rule and one I think all the drivers follow at
> > this point.
> 
> no, what I'm trying to avoid is having two virtual mappings to the
> same physical page with different cache attributes.  This is not
> allowed on some architectures (like ARM)

Nor x86... that's a matter for the core architecture code to deal with
not the drivers.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/