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. Signed-off-by: Daniel Stone <[email protected]> Reviewed-by: Pekka Paalanen <[email protected]> --- libweston/compositor-drm.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) v10: Merged Pixman refcounting patch into this, added unref on exit. diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c index e4c91f22..57ee9c67 100644 --- a/libweston/compositor-drm.c +++ b/libweston/compositor-drm.c @@ -138,6 +138,8 @@ 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; @@ -378,6 +380,8 @@ 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", @@ -461,6 +465,13 @@ 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) { @@ -470,7 +481,7 @@ 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); @@ -478,6 +489,7 @@ 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); @@ -552,9 +564,13 @@ 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 */ + drm_fb_destroy_dumb(fb); break; case BUFFER_CLIENT: gbm_bo_destroy(fb->bo); @@ -715,7 +731,7 @@ drm_output_render_pixman(struct drm_output *output, pixman_region32_t *damage) output->current_image ^= 1; - output->next = output->dumb[output->current_image]; + output->next = drm_fb_ref(output->dumb[output->current_image]); pixman_renderer_output_set_buffer(&output->base, output->image[output->current_image]); @@ -2060,7 +2076,7 @@ drm_output_init_pixman(struct drm_output *output, struct drm_backend *b) err: for (i = 0; i < ARRAY_LENGTH(output->dumb); i++) { if (output->dumb[i]) - drm_fb_destroy_dumb(output->dumb[i]); + drm_fb_unref(output->dumb[i]); if (output->image[i]) pixman_image_unref(output->image[i]); @@ -2080,8 +2096,8 @@ drm_output_fini_pixman(struct drm_output *output) pixman_region32_fini(&output->previous_damage); for (i = 0; i < ARRAY_LENGTH(output->dumb); i++) { - drm_fb_destroy_dumb(output->dumb[i]); pixman_image_unref(output->image[i]); + drm_fb_unref(output->dumb[i]); output->dumb[i] = NULL; output->image[i] = NULL; } @@ -2570,6 +2586,12 @@ drm_output_deinit(struct weston_output *base) struct drm_output *output = to_drm_output(base); struct drm_backend *b = to_drm_backend(base->compositor); + /* output->next must not be set here; + * destroy_pending/disable_pending exist to guarantee exactly this. */ + assert(!output->next); + drm_fb_unref(output->current); + output->current = NULL; + if (b->use_pixman) drm_output_fini_pixman(output); else -- 2.12.2 _______________________________________________ wayland-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/wayland-devel
