Sometimes we need to duplicate an existing drm_fb, e.g. when pageflipping to the same buffer to kickstart the repaint loop. To handle situations like these, and simplify resource management for dumb and cursor buffers, refcount drm_fb.
drm_fb_get_from_bo has a path where it may reuse a drm_fb, if the BO has been imported and not released yet. As drm_fb_unref now relies on actual refcounting (backed up by asserts), we add a balancing drm_fb_ref() to the path where we return a reused drm_fb. Differential Revision: https://phabricator.freedesktop.org/D1491 Signed-off-by: Daniel Stone <dani...@collabora.com> Reviewed-by: Pekka Paalanen <pekka.paala...@collabora.co.uk> --- libweston/compositor-drm.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c index 2e64785..bfb3293 100644 --- a/libweston/compositor-drm.c +++ b/libweston/compositor-drm.c @@ -137,6 +137,8 @@ enum drm_fb_type { struct drm_fb { enum drm_fb_type type; + int refcnt; + uint32_t fb_id, stride, handle, size; const struct pixel_format_info *format; int width, height; @@ -336,6 +338,8 @@ drm_fb_create_dumb(struct drm_backend *b, int width, int height, if (!fb) return NULL; + fb->refcnt = 1; + fb->format = pixel_format_get_info(format); if (!fb->format) { weston_log("failed to look up format 0x%lx\n", @@ -419,6 +423,13 @@ err_fb: } static struct drm_fb * +drm_fb_ref(struct drm_fb *fb) +{ + fb->refcnt++; + return fb; +} + +static struct drm_fb * drm_fb_get_from_bo(struct gbm_bo *bo, struct drm_backend *backend, uint32_t format, enum drm_fb_type type) { @@ -428,7 +439,7 @@ drm_fb_get_from_bo(struct gbm_bo *bo, struct drm_backend *backend, if (fb) { assert(fb->type == type); - return fb; + return drm_fb_ref(fb); } fb = zalloc(sizeof *fb); @@ -436,6 +447,7 @@ drm_fb_get_from_bo(struct gbm_bo *bo, struct drm_backend *backend, return NULL; fb->type = type; + fb->refcnt = 1; fb->bo = bo; fb->width = gbm_bo_get_width(bo); @@ -510,6 +522,10 @@ drm_fb_unref(struct drm_fb *fb) if (!fb) return; + assert(fb->refcnt > 0); + if (--fb->refcnt > 0) + return; + switch (fb->type) { case BUFFER_PIXMAN_DUMB: /* nothing: pixman buffers are destroyed manually */ -- 2.9.3 _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/wayland-devel
