Re: [PATCH] omap2+: add drm device

Gross, Andy
2012-05-24T15:09:38Z

On Thu, May 24, 2012 at 7:13 AM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
> On Thu, 2012-05-24 at 02:44 -0600, Rob Clark wrote:
>
>> but other drivers *can* use tiler, thanks to dmabuf.. I have omap4iss
>> v4l2 camera working w/ tiler buffers on my pandaboard, for example.
>>
>> Maybe fbdev is an exception to the rule because it has no way for
>> userspace to pass it a buffer to use.  But on the other hand it is a
>> legacy API so I'm not sure if it is worth loosing too much sleep over
>> that.
>
> I'm not that familiar with dmabuf, but are you saying it's not possible
> for a kernel driver to request the buffers? They _must_ come from the
> userspace?
>
> Anyway, even if it would be possible, if the tiler is a part of omapdrm
> we need omapdrm to get and use the tiler buffers. And we can't have
> omapdrm running when using omapfb, because they both use omapdss.

And that is a good point. The DSS is kind of a sticking point to anyone
having to enable DRM to get Tiler. However, omapfb doesn't currently utilize
DMM/Tiler features. Can't we defer generalizing until there is a
requirement for it?

Andy