diff options
| author | Daniel Stone <daniels@collabora.com> | 2017-04-17 13:11:13 +0100 |
|---|---|---|
| committer | Daniel Stone <daniels@collabora.com> | 2017-05-02 19:08:29 +0100 |
| commit | 497ab787e5ab56c630014a20b43bfab16e3b43aa (patch) | |
| tree | 3926e32647f09928fd79b91877a401fe2d120ed1 | |
| parent | c84b17c5761059f7c8490bf6a4e0a2beec74f9b1 (diff) | |
| download | kmscube-497ab787e5ab56c630014a20b43bfab16e3b43aa.tar.gz | |
atomic: Use CPU-side KMS fence synchronisation
Atomic does not let us have multiple requests in flight at once; if we
don't synchronise with the request completion on the CPU side, we can
get -EBUSY from the atomic commit.
We already have everything required to do this, namely the out-fence
from the last commit. Block on that with a CPU-side wait before we call
atomic commit, to make sure we'll never attempt to queue an atomic
commit before the previous one has completed.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
| -rw-r--r-- | common.c | 1 | ||||
| -rw-r--r-- | common.h | 1 | ||||
| -rw-r--r-- | drm-atomic.c | 21 |
3 files changed, 22 insertions, 1 deletions
@@ -155,6 +155,7 @@ int init_egl(struct egl *egl, const struct gbm *gbm) get_proc_dpy(EGL_KHR_fence_sync, eglCreateSyncKHR); get_proc_dpy(EGL_KHR_fence_sync, eglDestroySyncKHR); get_proc_dpy(EGL_KHR_fence_sync, eglWaitSyncKHR); + get_proc_dpy(EGL_KHR_fence_sync, eglClientWaitSyncKHR); get_proc_dpy(EGL_ANDROID_native_fence_sync, eglDupNativeFenceFDANDROID); printf("Using display %p with EGL version %d.%d\n", @@ -79,6 +79,7 @@ struct egl { PFNEGLCREATESYNCKHRPROC eglCreateSyncKHR; PFNEGLDESTROYSYNCKHRPROC eglDestroySyncKHR; PFNEGLWAITSYNCKHRPROC eglWaitSyncKHR; + PFNEGLCLIENTWAITSYNCKHRPROC eglClientWaitSyncKHR; PFNEGLDUPNATIVEFENCEFDANDROIDPROC eglDupNativeFenceFDANDROID; void (*draw)(unsigned i); diff --git a/drm-atomic.c b/drm-atomic.c index 0f3c4f2..65caacd 100644 --- a/drm-atomic.c +++ b/drm-atomic.c @@ -210,6 +210,7 @@ static int atomic_run(const struct gbm *gbm, const struct egl *egl) if (drm.kms_out_fence_fd != -1) { kms_fence = create_fence(egl, drm.kms_out_fence_fd); + assert(kms_fence); /* driver now has ownership of the fence fd: */ drm.kms_out_fence_fd = -1; @@ -220,7 +221,6 @@ static int atomic_run(const struct gbm *gbm, const struct egl *egl) * the buffer that is still on screen. */ egl->eglWaitSyncKHR(egl->display, kms_fence, 0); - egl->eglDestroySyncKHR(egl->display, kms_fence); } egl->draw(i++); @@ -229,6 +229,7 @@ static int atomic_run(const struct gbm *gbm, const struct egl *egl) * signaled when gpu rendering done */ gpu_fence = create_fence(egl, EGL_NO_NATIVE_FENCE_FD_ANDROID); + assert(gpu_fence); eglSwapBuffers(egl->display, egl->surface); @@ -246,6 +247,24 @@ static int atomic_run(const struct gbm *gbm, const struct egl *egl) return -1; } + if (kms_fence) { + EGLint status; + + /* Wait on the CPU side for the _previous_ commit to + * complete before we post the flip through KMS, as + * atomic will reject the commit if we post a new one + * whilst the previous one is still pending. + */ + do { + status = egl->eglClientWaitSyncKHR(egl->display, + kms_fence, + 0, + EGL_FOREVER_KHR); + } while (status != EGL_CONDITION_SATISFIED_KHR); + + egl->eglDestroySyncKHR(egl->display, kms_fence); + } + /* * Here you could also update drm plane layers if you want * hw composition |