[PATCH v4 06/13] drm/cirrus: Use drm_gem_shmem_vmap_local() in damage handling

[Daniel Vetter]

On Mon, Jan 11, 2021 at 06:00:42PM +0100, Daniel Vetter wrote:
> On Fri, Jan 08, 2021 at 10:43:33AM +0100, Thomas Zimmermann wrote:
> > Damage handling in cirrus requires a short-term mapping of the source
> > BO. Use drm_gem_shmem_vmap_local().
> > 
> > Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> 
> Hm more possible errors that we don't report to userspace ... Why don't we
> vmap/vunmap these in prepare/cleanup_fb? Generally we'd want a long-term
> vmap here to make sure this all works nicely.
> 
> Since it's nothing new, on this patch:
> 
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Ok, also strike this r-b here. This is called from that atomic commit
paths, and we cannot call dma_resv_lock here. This should splat with
lockdep enabled against the dma-fence annotations I've merged, I'm kinda
surprised it doesn't?
-Daniel

> 
> > ---
> >  drivers/gpu/drm/tiny/cirrus.c | 10 ++++++++--
> >  1 file changed, 8 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
> > index a043e602199e..21cd7056d45f 100644
> > --- a/drivers/gpu/drm/tiny/cirrus.c
> > +++ b/drivers/gpu/drm/tiny/cirrus.c
> > @@ -315,6 +315,7 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
> >  			       struct drm_rect *rect)
> >  {
> >  	struct cirrus_device *cirrus = to_cirrus(fb->dev);
> > +	struct drm_gem_object *obj = fb->obj[0];
> >  	struct dma_buf_map map;
> >  	void *vmap;
> >  	int idx, ret;
> > @@ -323,9 +324,12 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
> >  	if (!drm_dev_enter(&cirrus->dev, &idx))
> >  		goto out;
> >  
> > -	ret = drm_gem_shmem_vmap(fb->obj[0], &map);
> > +	ret = dma_resv_lock(obj->resv, NULL);
> >  	if (ret)
> >  		goto out_dev_exit;
> > +	ret = drm_gem_shmem_vmap_local(fb->obj[0], &map);
> > +	if (ret)
> > +		goto out_dma_resv_unlock;
> >  	vmap = map.vaddr; /* TODO: Use mapping abstraction properly */
> >  
> >  	if (cirrus->cpp == fb->format->cpp[0])
> > @@ -345,9 +349,11 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
> >  	else
> >  		WARN_ON_ONCE("cpp mismatch");
> >  
> > -	drm_gem_shmem_vunmap(fb->obj[0], &map);
> >  	ret = 0;
> >  
> > +	drm_gem_shmem_vunmap_local(obj, &map);
> > +out_dma_resv_unlock:
> > +	dma_resv_unlock(obj->resv);
> >  out_dev_exit:
> >  	drm_dev_exit(idx);
> >  out:
> > -- 
> > 2.29.2
> > 
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch