In a couple of places currently, and with the intent to add more, we
update a pointer to a framebuffer to hold a new fb reference (evicting
the old).
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/drm_atomic.c | 8 ++------
include/drm/drm_framebuffer.h | 18 ++++++++++++++++++
2 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 89737e42fa83..19d7bcb88217 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1246,18 +1246,14 @@ void
drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state,
struct drm_framebuffer *fb)
{
- if (plane_state->fb)
- drm_framebuffer_unreference(plane_state->fb);
- if (fb)
- drm_framebuffer_reference(fb);
- plane_state->fb = fb;
-
if (fb)
DRM_DEBUG_ATOMIC("Set [FB:%d] for plane state %p\n",
fb->base.id, plane_state);
else
DRM_DEBUG_ATOMIC("Set [NOFB] for plane state %p\n",
plane_state);
+
+ drm_framebuffer_assign(&plane_state->fb, fb);
}
EXPORT_SYMBOL(drm_atomic_set_fb_for_plane);
diff --git a/include/drm/drm_framebuffer.h b/include/drm/drm_framebuffer.h
index b3141a0e609b..1ddfa2928802 100644
--- a/include/drm/drm_framebuffer.h
+++ b/include/drm/drm_framebuffer.h
@@ -251,6 +251,24 @@ static inline uint32_t
drm_framebuffer_read_refcount(struct drm_framebuffer *fb)
}
/**
+ * drm_framebuffer_assign - store a reference to the fb
+ * @p: location to store framebuffer
+ * @fb: new framebuffer (maybe NULL)
+ *
+ * This functions sets the location to store a reference to the framebuffer,
+ * unreferencing the framebuffer that was previously stored in that location.
+ */
+static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
+ struct drm_framebuffer *fb)
+{
+ if (fb)
+ drm_framebuffer_reference(fb);
+ if (*p)
+ drm_framebuffer_unreference(*p);
+ *p = fb;
+}
+
+/*
* drm_for_each_fb - iterate over all framebuffers
* @fb: the loop cursor
* @dev: the DRM device
--
2.10.2
