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@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@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