Commit 497ab787 authored by Daniel Stone's avatar Daniel Stone

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: 's avatarDaniel Stone <daniels@collabora.com>
Reviewed-by: 's avatarEmil Velikov <emil.velikov@collabora.com>
parent c84b17c5
......@@ -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);
......
......@@ -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
......
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