If the FB is backed by a GEM object with an dma-buf attached
we need to wait for any pending fences to signal before executing
the page flip.
The implementation is straight forward by deferring the flip to
a workqueue in that case.
Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
drivers/gpu/drm/imx/ipuv3-crtc.c | 63 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 61 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/imx/ipuv3-crtc.c b/drivers/gpu/drm/imx/ipuv3-crtc.c
index a07e656e9a32..30214c0e7d93 100644
--- a/drivers/gpu/drm/imx/ipuv3-crtc.c
+++ b/drivers/gpu/drm/imx/ipuv3-crtc.c
@@ -22,6 +22,8 @@
#include <linux/fb.h>
#include <linux/clk.h>
#include <linux/errno.h>
+#include <linux/reservation.h>
+#include <linux/dma-buf.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_fb_cma_helper.h>
@@ -34,12 +36,18 @@
enum ipu_flip_status {
IPU_FLIP_NONE,
IPU_FLIP_PENDING,
+ IPU_FLIP_SUBMITTED,
};
struct ipu_flip_work {
struct work_struct unref_work;
struct drm_gem_object *bo;
struct drm_pending_vblank_event *page_flip_event;
+ struct work_struct fence_work;
+ struct ipu_crtc *crtc;
+ struct fence *excl;
+ unsigned shared_count;
+ struct fence **shared;
};
struct ipu_crtc {
@@ -125,11 +133,31 @@ static void ipu_flip_unref_work_func(struct work_struct
*__work)
kfree(work);
}
+static void ipu_flip_fence_work_func(struct work_struct *__work)
+{
+ struct ipu_flip_work *work =
+ container_of(__work, struct ipu_flip_work, fence_work);
+ int i;
+
+ /* wait for all fences attached to the FB obj to signal */
+ if (work->excl) {
+ fence_wait(work->excl, false);
+ fence_put(work->excl);
+ }
+ for (i = 0; i < work->shared_count; i++) {
+ fence_wait(work->shared[i], false);
+ fence_put(work->shared[i]);
+ }
+
+ work->crtc->flip_state = IPU_FLIP_SUBMITTED;
+}
+
static int ipu_page_flip(struct drm_crtc *crtc,
struct drm_framebuffer *fb,
struct drm_pending_vblank_event *event,
uint32_t page_flip_flags)
{
+ struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
struct ipu_flip_work *flip_work;
int ret;
@@ -158,10 +186,41 @@ static int ipu_page_flip(struct drm_crtc *crtc,
drm_gem_object_reference(flip_work->bo);
ipu_crtc->flip_work = flip_work;
- ipu_crtc->flip_state = IPU_FLIP_PENDING;
+ /*
+ * If the object has a DMABUF attached, we need to wait on its fences
+ * if there are any.
+ */
+ if (cma_obj->base.dma_buf) {
+ INIT_WORK(&flip_work->fence_work, ipu_flip_fence_work_func);
+ flip_work->crtc = ipu_crtc;
+
+ ret = reservation_object_get_fences_rcu(
+ cma_obj->base.dma_buf->resv, &flip_work->excl,
+ &flip_work->shared_count, &flip_work->shared);
+
+ if (unlikely(ret)) {
+ DRM_ERROR("failed to get fences for buffer\n");
+ goto free_flip_work;
+ }
+
+ /* No need to queue the worker if the are no fences */
+ if (!flip_work->excl && !flip_work->shared_count) {
+ ipu_crtc->flip_state = IPU_FLIP_SUBMITTED;
+ } else {
+ ipu_crtc->flip_state = IPU_FLIP_PENDING;
+ queue_work(ipu_crtc->flip_queue,
+ &flip_work->fence_work);
+ }
+ } else {
+ ipu_crtc->flip_state = IPU_FLIP_SUBMITTED;
+ }
return 0;
+free_flip_work:
+ drm_gem_object_unreference_unlocked(flip_work->bo);
+ kfree(flip_work);
+ ipu_crtc->flip_work = NULL;
put_vblank:
imx_drm_crtc_vblank_put(ipu_crtc->imx_crtc);
@@ -266,7 +325,7 @@ static irqreturn_t ipu_irq_handler(int irq, void *dev_id)
imx_drm_handle_vblank(ipu_crtc->imx_crtc);
- if (ipu_crtc->flip_state == IPU_FLIP_PENDING) {
+ if (ipu_crtc->flip_state == IPU_FLIP_SUBMITTED) {
struct ipu_plane *plane = ipu_crtc->plane[0];
ipu_plane_set_base(plane, ipu_crtc->base.primary->fb,
--
2.7.0.rc3
