On Mon, Jan 11, 2021 at 05:53:41PM +0100, Daniel Vetter wrote:
> On Fri, Jan 08, 2021 at 10:43:32AM +0100, Thomas Zimmermann wrote:
> > Damage handling in mgag200 requires a short-term mapping of the source
> > BO. Use drm_gem_shmem_vmap_local().
> >
> > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
>
> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
On second thought, strike that r-b, I have a confused question.
>
> > ---
> > drivers/gpu/drm/mgag200/mgag200_mode.c | 16 +++++++++++++---
> > 1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
> > index 1dfc42170059..a33e28d4c5e9 100644
> > --- a/drivers/gpu/drm/mgag200/mgag200_mode.c
> > +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
> > @@ -1552,22 +1552,32 @@ mgag200_handle_damage(struct mga_device *mdev, struct drm_framebuffer *fb,
> > struct drm_rect *clip)
> > {
> > struct drm_device *dev = &mdev->base;
> > + struct drm_gem_object *obj = fb->obj[0];
> > struct dma_buf_map map;
> > void *vmap;
> > int ret;
> >
> > - ret = drm_gem_shmem_vmap(fb->obj[0], &map);
> > + ret = dma_resv_lock(obj->resv, NULL);
> > if (drm_WARN_ON(dev, ret))
> > - return; /* BUG: SHMEM BO should always be vmapped */
> > + return;
> > + ret = drm_gem_shmem_vmap_local(obj, &map);
> > + if (drm_WARN_ON(dev, ret))
> > + goto err_dma_resv_unlock; /* BUG: SHMEM BO should always be vmapped */
Why is this guaranteed? I tried to hunt for a vmap in mga200g code, and
dind't find any. I'd ahve expected something in prepare/finish_fb.
Also since this is not a vram-helper using driver, why convert it over to
vmap_local? I guess that should also be explained in the commit message a
bit better.
-Daniel
> > vmap = map.vaddr; /* TODO: Use mapping abstraction properly */
> >
> > drm_fb_memcpy_dstclip(mdev->vram, vmap, fb, clip);
> >
> > - drm_gem_shmem_vunmap(fb->obj[0], &map);
> > + drm_gem_shmem_vunmap_local(obj, &map);
> > + dma_resv_unlock(obj->resv);
> >
> > /* Always scanout image at VRAM offset 0 */
> > mgag200_set_startadd(mdev, (u32)0);
> > mgag200_set_offset(mdev, fb);
> > +
> > + return;
> > +
> > +err_dma_resv_unlock:
> > + dma_resv_unlock(obj->resv);
> > }
> >
> > static void
> > --
> > 2.29.2
> >
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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