[Mesa-dev] [PATCH kmscube 1/6] drm: Provide a failure path when getting the fb

[Ben Widawsky]

This is helpful for debugging as you will bail early with an error
message instead of a random SIGSEGV (or something more obscure).
---
 drm-atomic.c | 9 +++++++++
 drm-legacy.c | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/drm-atomic.c b/drm-atomic.c
index 27c6b1e..c06e52f 100644
--- a/drm-atomic.c
+++ b/drm-atomic.c
@@ -187,6 +187,11 @@ static int atomic_run(const struct gbm *gbm, const struct 
egl *egl)
        eglSwapBuffers(egl->display, egl->surface);
        bo = gbm_surface_lock_front_buffer(gbm->surface);
        fb = drm_fb_get_from_bo(bo);
+       if (!fb) {
+               printf("Failed to get a new framebuffer BO\n");
+               return -1;
+       }
+
 
        drm.kms_in_fence_fd = -1;
 
@@ -235,6 +240,10 @@ static int atomic_run(const struct gbm *gbm, const struct 
egl *egl)
 
                next_bo = gbm_surface_lock_front_buffer(gbm->surface);
                fb = drm_fb_get_from_bo(next_bo);
+               if (!fb) {
+                       printf("Failed to get a new framebuffer BO\n");
+                       return -1;
+               }
 
                /*
                 * Here you could also update drm plane layers if you want
diff --git a/drm-legacy.c b/drm-legacy.c
index 3b407f8..a0b419a 100644
--- a/drm-legacy.c
+++ b/drm-legacy.c
@@ -60,6 +60,10 @@ static int legacy_run(const struct gbm *gbm, const struct 
egl *egl)
        eglSwapBuffers(egl->display, egl->surface);
        bo = gbm_surface_lock_front_buffer(gbm->surface);
        fb = drm_fb_get_from_bo(bo);
+       if (!fb) {
+               fprintf(stderr, "Failed to get a new framebuffer BO\n");
+               return -1;
+       }
 
        /* set mode: */
        ret = drmModeSetCrtc(drm.fd, drm.crtc_id, fb->fb_id, 0, 0,
@@ -78,6 +82,10 @@ static int legacy_run(const struct gbm *gbm, const struct 
egl *egl)
                eglSwapBuffers(egl->display, egl->surface);
                next_bo = gbm_surface_lock_front_buffer(gbm->surface);
                fb = drm_fb_get_from_bo(next_bo);
+               if (!fb) {
+                       fprintf(stderr, "Failed to get a new framebuffer BO\n");
+                       return -1;
+               }
 
                /*
                 * Here you could also update drm plane layers if you want
-- 
2.12.2

_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev