drm/imx: implement fence sync

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>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
This commit is contained in:
Lucas Stach 2016-02-09 14:51:26 +01:00 committed by Philipp Zabel
parent 0a7ad343c8
commit 17a8d08df1

View file

@ -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 {
@ -123,11 +131,31 @@ 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;
@ -156,10 +184,41 @@ 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);
@ -263,7 +322,7 @@ 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,