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@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,