[PATCH 15/15] drm: omapdrm: gem: Implement dma_buf import

Laurent Pinchart laurent.pinchart at ideasonboard.com
Sat Dec 5 14:24:35 PST 2015


Hi Daniel,

On Saturday 05 December 2015 16:40:14 Daniel Vetter wrote:
> On Sat, Dec 05, 2015 at 12:27:19AM +0200, Laurent Pinchart wrote:
> > OMAP GEM objects backed by dma_buf reuse the current OMAP GEM object
> > support as much as possible. If the imported buffer is physically
> > contiguous its physical address will be used directly, reusing the
> > OMAP_BO_MEM_DMA_API code paths. Otherwise it will be mapped through the
> > TILER using a pages list created from the scatterlist instead of the
> > shmem backing storage.
> > 
> > Disallow exporting imported buffers for now as those code paths haven't
> > been verified. Use cases of such a feature are suspicious anyway.
> 
> If you export a buffer that's been imported the drm_prime.c helpers should
> dig out the original dma-buf again. You should never end up with a dma-buf
> -> omap gem bo -> dma-buf chain.
> 
> If that doesn't work then there's a bug somewhere ...

Very good point. I'll drop the check. Thank you for the review.

> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> > 
> >  drivers/gpu/drm/omapdrm/omap_drv.h        |   2 +
> >  drivers/gpu/drm/omapdrm/omap_gem.c        | 138 +++++++++++++++++++------
> >  drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c |  57 +++++++++---
> >  3 files changed, 163 insertions(+), 34 deletions(-)

-- 
Regards,

Laurent Pinchart



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