[PATCH 06/16] drm/omap: remove dma & vrfb rotation

[Laurent Pinchart]

Hi Tomi,

On Wednesday 24 May 2017 13:13:08 Tomi Valkeinen wrote:
> On 24/05/17 12:31, Laurent Pinchart wrote:
> > On Thursday 04 May 2017 13:23:22 Tomi Valkeinen wrote:
> >> We have three rotation methods supported by the SoCs with DSS: DMA,
> >> VRFB and TILER.
> >> 
> >> DMA rotation works in theory on all DSS platforms, but in practice it's
> >> unusable due to the huge amount of memory bandwidth it uses, and has
> >> never really been used.
> >> 
> >> VRFB is available on OMAP3, but is not supported by omapdrm, even though
> >> we have some code for it in the dispc driver.
> >> 
> >> TILER is supported on OMAP4/OMAP5/DRA7/AM5 platforms, but has some
> >> driver bugs.
> >> 
> >> To clean up the driver to help fixing the TILER issues, this patch drops
> >> the DMA and VRFB rotation support, leaving only TILER rotation.
> > 
> > I'm fine dropping DMA rotation, but I have mixed feelings about VRFB. Yes,
> > it doesn't work at the moment, but I know users of VRFB with the
> > omap_vout driver who would really like to switch to omapdrm. Porting VRFB
> > from omap_vout to omapdrm has been on my to-do list for a long time (with
> > a low priority unfortunately). As an added bonus, it would allow dropping
> > the omap_vout driver at some point.
> > 
> > What would you think about dropping DMA but keeping VRFB for now ?
> 
> This patch doesn't remove that much about vrfb, just the row/pix inc
> calculations. The main vrfb file is still there, for omapfb. I'm happy
> to add it back when someone has a working prototype for omapdrm+vrfb,
> but to be honest, I won't hold my breath =).
> 
> I really want to clean up the dispc driver as much as possible, as it's
> such a messy piece of code, supporting so many DSS IP versions. I
> believe we'll get a cleaner version if we add the vrfb back from scratch.

Acked-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

-- 
Regards,

Laurent Pinchart