Re: [PATCH 0/9] TI DMM-TILER driver

David Sin
2010-12-16T17:25:21Z

On Thu, Dec 16, 2010 at 11:25:31AM -0600, David Sin wrote:
> On Thu, Dec 16, 2010 at 02:34:05PM +0100, Arnd Bergmann wrote:
> > On Monday 06 December 2010, David Sin wrote:
> > > Tiling and Isometric Lightweight Engine for Rotation (TILER) driver
> > > =====
> > >
> > > Dynamic Memory Manager (DMM) is a hardware block made by Texas Instruments.
> > > Within the DMM exists at least one TILER hardware component. Its purpose is to
> > > organize video/image memory in a 2-dimensional fashion to limit memory
> > > bandwidth and facilitate 0 effort rotation and mirroring. The TILER driver
> > > facilitates allocating, freeing, as well as mapping 2D blocks (areas) in the
> > > TILER container(s). It also facilitates rotating and mirroring the allocated
> > > blocks or its rectangular subsections.
> >
> > How does this relate to DRM/GEM? I don't understand too much about graphics
> > drivers, but it does sound like there is some overlap in functionality.
> >
> > I guess at the very least the DMM should live in drivers/gpu/ instead of
> > drivers/misc, but perhaps it could be integrated more closely with the
> > existing code there.
> >
> > Arnd
> Do you know if anyone on your team is familiar with DRM/GEM (grap ext mgr)
> for x86? I'm trying to understand the differences and make a case that
> it's not the same as DMM/TILER.
>
> thanks,
> --
> David Sin
Hi Arnd,
I'm not sure exactly how DRM/GEM works.. What functionality do you think is
overlapping? The main feature, aside from reduced page accesses, of the DMM
hw block is to provide physically contiguous 2 dimensional memory blocks for
image and video processing. This hw sits between the interconnect and the
ext memory interface in the OMAP, and contains an MMU-like address traslator
for "virtually" physically contiguous memory and sdram pages.

thank you for your comments.

BR,
--
David Sin