staging: drm/omap: send page-flip event after endwin

The endwin irq indicates that DSS has finished scanning out a buffer.
Use this to trigger page-flip event to userspace, so this happens
only *after* the previous buffer is finished.

Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 67 insertions, 18 deletions

diff --git a/drivers/staging/omapdrm/omap_crtc.c b/drivers/staging/omapdrm/omap_crtc.c
index 17ca163e5896..13e3c7f7d2b9 100644
--- a/drivers/staging/omapdrm/omap_crtc.c
+++ b/drivers/staging/omapdrm/omap_crtc.c
@@ -118,25 +118,21 @@ static void omap_crtc_load_lut(struct drm_crtc *crtc)
 {
 }
 
-static void page_flip_cb(void *arg)
+static void vblank_cb(void *arg)
 {
+        static uint32_t sequence = 0;
         struct drm_crtc *crtc = arg;
         struct drm_device *dev = crtc->dev;
         struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
         struct drm_pending_vblank_event *event = omap_crtc->event;
-        struct drm_framebuffer *old_fb = omap_crtc->old_fb;
-        struct timeval now;
         unsigned long flags;
+        struct timeval now;
 
         WARN_ON(!event);
 
         omap_crtc->event = NULL;
-        omap_crtc->old_fb = NULL;
-
-        omap_crtc_mode_set_base(crtc, crtc->x, crtc->y, old_fb);
 
         /* wakeup userspace */
-        /* TODO: this should happen *after* flip in vsync IRQ handler */
         if (event) {
                 spin_lock_irqsave(&dev->event_lock, flags);
                 event->event.sequence = drm_vblank_count_and_time(
@@ -150,6 +146,23 @@ static void page_flip_cb(void *arg)
         }
 }
 
+static void page_flip_cb(void *arg)
+{
+        struct drm_crtc *crtc = arg;
+        struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
+        struct drm_framebuffer *old_fb = omap_crtc->old_fb;
+
+        omap_crtc->old_fb = NULL;
+
+        omap_crtc_mode_set_base(crtc, crtc->x, crtc->y, old_fb);
+
+        /* really we'd like to setup the callback atomically w/ setting the
+         * new scanout buffer to avoid getting stuck waiting an extra vblank
+         * cycle.. for now go for correctness and later figure out speed..
+         */
+        omap_plane_on_endwin(omap_crtc->plane, vblank_cb, crtc);
+}
+
 static int omap_crtc_page_flip_locked(struct drm_crtc *crtc,
                  struct drm_framebuffer *fb,
                  struct drm_pending_vblank_event *event)
diff --git a/drivers/staging/omapdrm/omap_drv.h b/drivers/staging/omapdrm/omap_drv.h
index 21e48cf430f4..b7e0f0773003 100644
--- a/drivers/staging/omapdrm/omap_drv.h
+++ b/drivers/staging/omapdrm/omap_drv.h
@@ -85,6 +85,8 @@ int omap_plane_mode_set(struct drm_plane *plane,
                 unsigned int crtc_w, unsigned int crtc_h,
                 uint32_t src_x, uint32_t src_y,
                 uint32_t src_w, uint32_t src_h);
+void omap_plane_on_endwin(struct drm_plane *plane,
+                void (*fxn)(void *), void *arg);
 
 struct drm_encoder *omap_encoder_init(struct drm_device *dev,
                 struct omap_overlay_manager *mgr);
diff --git a/drivers/staging/omapdrm/omap_plane.c b/drivers/staging/omapdrm/omap_plane.c
index 9b3bfa02a91c..7997be74010d 100644
--- a/drivers/staging/omapdrm/omap_plane.c
+++ b/drivers/staging/omapdrm/omap_plane.c
@@ -31,6 +31,11 @@
  * plane funcs
  */
 
+struct callback {
+        void (*fxn)(void *);
+        void *arg;
+};
+
 #define to_omap_plane(x) container_of(x, struct omap_plane, base)
 
 struct omap_plane {
@@ -58,6 +63,9 @@ struct omap_plane {
 
         /* for deferred unpin when we need to wait for scanout complete irq */
         struct work_struct work;
+
+        /* callback on next endwin irq */
+        struct callback endwin;
 };
 
 /* map from ovl->id to the irq we are interested in for scanout-done */
@@ -84,6 +92,7 @@ static void unpin_worker(struct work_struct *work)
 {
         struct omap_plane *omap_plane =
                         container_of(work, struct omap_plane, work);
+        struct callback endwin;
 
         mutex_lock(&omap_plane->unpin_mutex);
         DBG("unpinning %d of %d", omap_plane->num_unpins,
@@ -96,7 +105,28 @@ static void unpin_worker(struct work_struct *work)
                 drm_gem_object_unreference_unlocked(bo);
                 omap_plane->num_unpins--;
         }
+        endwin = omap_plane->endwin;
+        omap_plane->endwin.fxn = NULL;
         mutex_unlock(&omap_plane->unpin_mutex);
+
+        if (endwin.fxn)
+                endwin.fxn(endwin.arg);
+}
+
+static void install_irq(struct drm_plane *plane)
+{
+        struct omap_plane *omap_plane = to_omap_plane(plane);
+        struct omap_overlay *ovl = omap_plane->ovl;
+        int ret;
+
+        ret = omap_dispc_register_isr(dispc_isr, plane, id2irq[ovl->id]);
+
+        /*
+         * omapdss has upper limit on # of registered irq handlers,
+         * which we shouldn't hit.. but if we do the limit should
+         * be raised or bad things happen:
+         */
+        WARN_ON(ret == -EBUSY);
 }
 
 /* push changes down to dss2 */
@@ -146,17 +176,8 @@ static int commit(struct drm_plane *plane)
                  * NOTE: really this should be atomic w/ mgr->apply() but
                  * omapdss does not expose such an API
                  */
-                if (omap_plane->num_unpins > 0) {
-                        ret = omap_dispc_register_isr(dispc_isr,
-                                plane, id2irq[ovl->id]);
-                }
-
-                /*
-                 * omapdss has upper limit on # of registered irq handlers,
-                 * which we shouldn't hit.. but if we do the limit should
-                 * be raised or bad things happen:
-                 */
-                WARN_ON(ret == -EBUSY);
+                if (omap_plane->num_unpins > 0)
+                        install_irq(plane);
 
         } else {
                 struct omap_drm_private *priv = dev->dev_private;
@@ -375,6 +396,19 @@ int omap_plane_dpms(struct drm_plane *plane, int mode)
         return r;
 }
 
+void omap_plane_on_endwin(struct drm_plane *plane,
+                void (*fxn)(void *), void *arg)
+{
+        struct omap_plane *omap_plane = to_omap_plane(plane);
+
+        mutex_lock(&omap_plane->unpin_mutex);
+        omap_plane->endwin.fxn = fxn;
+        omap_plane->endwin.arg = arg;
+        mutex_unlock(&omap_plane->unpin_mutex);
+
+        install_irq(plane);
+}
+
 static const struct drm_plane_funcs omap_plane_funcs = {
                 .update_plane = omap_plane_update,
                 .disable_plane = omap_plane_disable,