drm: omapdrm: Apply settings synchronously

The omapdrm driver implements a mechanism to apply new settings (due to
plane update, plane disable, plane property set, CRTC mode set or CRTC
DPMS) asynchronously. While this improves performance, it adds a level
of complexity that makes transition to the atomic update API close to
impossible. Furthermore the atomic update API requires part of the apply
operations to be synchronous (such as pinning the framebuffers), so the
current implementation needs to be changed.

Simplify the CRTC and plane code by making updates synchronous to
prepare for the switch to the atomic update API. Asynchronous update
will be implemented in a second step.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/omap_drv.c

@@ -550,7 +550,6 @@ static int dev_load(struct drm_device *dev, unsigned long flags)
 static int dev_unload(struct drm_device *dev)
 {
 	struct omap_drm_private *priv = dev->dev_private;
-	int i;
 
 	DBG("unload: dev=%p", dev);
 
@@ -559,10 +558,6 @@ static int dev_unload(struct drm_device *dev)
 	if (priv->fbdev)
 		omap_fbdev_free(dev);
 
-	/* flush crtcs so the fbs get released */
-	for (i = 0; i < priv->num_crtcs; i++)
-		omap_crtc_flush(priv->crtcs[i]);
-
 	omap_modeset_free(dev);
 	omap_gem_deinit(dev);
 

drivers/gpu/drm/omapdrm/omap_drv.h

@@ -50,21 +50,6 @@ struct omap_drm_window {
 	uint32_t src_w, src_h;
 };
 
-/* Once GO bit is set, we can't make further updates to shadowed registers
- * until the GO bit is cleared.  So various parts in the kms code that need
- * to update shadowed registers queue up a pair of callbacks, pre_apply
- * which is called before setting GO bit, and post_apply that is called
- * after GO bit is cleared.  The crtc manages the queuing, and everyone
- * else goes thru omap_crtc_apply() using these callbacks so that the
- * code which has to deal w/ GO bit state is centralized.
- */
-struct omap_drm_apply {
-	struct list_head pending_node, queued_node;
-	bool queued;
-	void (*pre_apply)(struct omap_drm_apply *apply);
-	void (*post_apply)(struct omap_drm_apply *apply);
-};
-
 /* For transiently registering for different DSS irqs that various parts
  * of the KMS code need during setup/configuration.  We these are not
  * necessarily the same as what drm_vblank_get/put() are requesting, and
@@ -153,13 +138,12 @@ void omap_fbdev_free(struct drm_device *dev);
 
 const struct omap_video_timings *omap_crtc_timings(struct drm_crtc *crtc);
 enum omap_channel omap_crtc_channel(struct drm_crtc *crtc);
-int omap_crtc_apply(struct drm_crtc *crtc,
-		struct omap_drm_apply *apply);
+int omap_crtc_flush(struct drm_crtc *crtc);
+int omap_crtc_queue_unpin(struct drm_crtc *crtc, struct drm_framebuffer *fb);
 void omap_crtc_pre_init(void);
 void omap_crtc_pre_uninit(void);
 struct drm_crtc *omap_crtc_init(struct drm_device *dev,
 		struct drm_plane *plane, enum omap_channel channel, int id);
-void omap_crtc_flush(struct drm_crtc *crtc);
 
 struct drm_plane *omap_plane_init(struct drm_device *dev,
 		int id, enum drm_plane_type type);
@@ -169,8 +153,7 @@ int omap_plane_mode_set(struct drm_plane *plane,
 			int crtc_x, int crtc_y,
 			unsigned int crtc_w, unsigned int crtc_h,
 			unsigned int src_x, unsigned int src_y,
-			unsigned int src_w, unsigned int src_h,
-			void (*fxn)(void *), void *arg);
+			unsigned int src_w, unsigned int src_h);
 void omap_plane_install_properties(struct drm_plane *plane,
 		struct drm_mode_object *obj);
 int omap_plane_set_property(struct drm_plane *plane,

drivers/gpu/drm/omapdrm/omap_plane.c

@@ -17,8 +17,6 @@
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "drm_flip_work.h"
-
 #include "omap_drv.h"
 #include "omap_dmm_tiler.h"
 
@@ -32,11 +30,6 @@
  * plane funcs
  */
 
-struct callback {
-	void (*fxn)(void *);
-	void *arg;
-};
-
 #define to_omap_plane(x) container_of(x, struct omap_plane, base)
 
 struct omap_plane {
@@ -44,7 +37,6 @@ struct omap_plane {
 	int id;  /* TODO rename omap_plane -> omap_plane_id in omapdss so I can use the enum */
 	const char *name;
 	struct omap_overlay_info info;
-	struct omap_drm_apply apply;
 
 	/* position/orientation of scanout within the fb: */
 	struct omap_drm_window win;
@@ -57,40 +49,19 @@ struct omap_plane {
 	uint32_t formats[32];
 
 	struct omap_drm_irq error_irq;
-
-	/* for deferring bo unpin's until next post_apply(): */
-	struct drm_flip_work unpin_work;
-
-	// XXX maybe get rid of this and handle vblank in crtc too?
-	struct callback apply_done_cb;
 };
 
-static void omap_plane_unpin_worker(struct drm_flip_work *work, void *val)
-{
-	struct omap_plane *omap_plane =
-			container_of(work, struct omap_plane, unpin_work);
-	struct drm_device *dev = omap_plane->base.dev;
-
-	/*
-	 * omap_framebuffer_pin/unpin are always called from priv->wq,
-	 * so there's no need for locking here.
-	 */
-	omap_framebuffer_unpin(val);
-	mutex_lock(&dev->mode_config.mutex);
-	drm_framebuffer_unreference(val);
-	mutex_unlock(&dev->mode_config.mutex);
-}
-
 /* update which fb (if any) is pinned for scanout */
-static int omap_plane_update_pin(struct drm_plane *plane,
-				 struct drm_framebuffer *fb)
+static int omap_plane_update_pin(struct drm_plane *plane)
 {
 	struct omap_plane *omap_plane = to_omap_plane(plane);
 	struct drm_framebuffer *pinned_fb = omap_plane->pinned_fb;
-
-	if (pinned_fb != fb) {
+	struct drm_framebuffer *fb = omap_plane->enabled ? plane->fb : NULL;
 	int ret = 0;
 
+	if (pinned_fb == fb)
+		return 0;
+
 	DBG("%p -> %p", pinned_fb, fb);
 
 	if (fb) {
@@ -99,7 +70,7 @@ static int omap_plane_update_pin(struct drm_plane *plane,
 	}
 
 	if (pinned_fb)
-			drm_flip_work_queue(&omap_plane->unpin_work, pinned_fb);
+		omap_crtc_queue_unpin(plane->crtc, pinned_fb);
 
 	if (ret) {
 		dev_err(plane->dev->dev, "could not swap %p -> %p\n",
@@ -110,38 +81,34 @@ static int omap_plane_update_pin(struct drm_plane *plane,
 	}
 
 	omap_plane->pinned_fb = fb;
-	}
 
 	return 0;
 }
 
-static void omap_plane_pre_apply(struct omap_drm_apply *apply)
+static int omap_plane_setup(struct omap_plane *omap_plane)
 {
-	struct omap_plane *omap_plane =
-			container_of(apply, struct omap_plane, apply);
-	struct omap_drm_window *win = &omap_plane->win;
+	struct omap_overlay_info *info = &omap_plane->info;
 	struct drm_plane *plane = &omap_plane->base;
 	struct drm_device *dev = plane->dev;
-	struct omap_overlay_info *info = &omap_plane->info;
 	struct drm_crtc *crtc = plane->crtc;
-	enum omap_channel channel;
-	bool enabled = omap_plane->enabled && crtc;
 	int ret;
 
-	DBG("%s, enabled=%d", omap_plane->name, enabled);
+	DBG("%s, enabled=%d", omap_plane->name, omap_plane->enabled);
 
 	/* if fb has changed, pin new fb: */
-	omap_plane_update_pin(plane, enabled ? plane->fb : NULL);
+	ret = omap_plane_update_pin(plane);
+	if (ret)
+		return ret;
+
+	dispc_runtime_get();
 
-	if (!enabled) {
+	if (!omap_plane->enabled) {
 		dispc_ovl_enable(omap_plane->id, false);
-		return;
+		goto done;
 	}
 
-	channel = omap_crtc_channel(crtc);
-
 	/* update scanout: */
-	omap_framebuffer_update_scanout(plane->fb, win, info);
+	omap_framebuffer_update_scanout(plane->fb, &omap_plane->win, info);
 
 	DBG("%dx%d -> %dx%d (%d)", info->width, info->height,
 			info->out_width, info->out_height,
@@ -149,43 +116,22 @@ static void omap_plane_pre_apply(struct omap_drm_apply *apply)
 	DBG("%d,%d %pad %pad", info->pos_x, info->pos_y,
 			&info->paddr, &info->p_uv_addr);
 
-	dispc_ovl_set_channel_out(omap_plane->id, channel);
+	dispc_ovl_set_channel_out(omap_plane->id,
+				  omap_crtc_channel(crtc));
 
 	/* and finally, update omapdss: */
 	ret = dispc_ovl_setup(omap_plane->id, info, false,
 			      omap_crtc_timings(crtc), false);
 	if (ret) {
 		dev_err(dev->dev, "dispc_ovl_setup failed: %d\n", ret);
-		return;
+		goto done;
 	}
 
 	dispc_ovl_enable(omap_plane->id, true);
-}
-
-static void omap_plane_post_apply(struct omap_drm_apply *apply)
-{
-	struct omap_plane *omap_plane =
-			container_of(apply, struct omap_plane, apply);
-	struct drm_plane *plane = &omap_plane->base;
-	struct omap_drm_private *priv = plane->dev->dev_private;
-	struct callback cb;
 
-	cb = omap_plane->apply_done_cb;
-	omap_plane->apply_done_cb.fxn = NULL;
-
-	drm_flip_work_commit(&omap_plane->unpin_work, priv->wq);
-
-	if (cb.fxn)
-		cb.fxn(cb.arg);
-}
-
-static int omap_plane_apply(struct drm_plane *plane)
-{
-	if (plane->crtc) {
-		struct omap_plane *omap_plane = to_omap_plane(plane);
-		return omap_crtc_apply(plane->crtc, &omap_plane->apply);
-	}
-	return 0;
+done:
+	dispc_runtime_put();
+	return ret;
 }
 
 int omap_plane_mode_set(struct drm_plane *plane,
@@ -193,8 +139,7 @@ int omap_plane_mode_set(struct drm_plane *plane,
 			int crtc_x, int crtc_y,
 			unsigned int crtc_w, unsigned int crtc_h,
 			unsigned int src_x, unsigned int src_y,
-			unsigned int src_w, unsigned int src_h,
-			void (*fxn)(void *), void *arg)
+			unsigned int src_w, unsigned int src_h)
 {
 	struct omap_plane *omap_plane = to_omap_plane(plane);
 	struct omap_drm_window *win = &omap_plane->win;
@@ -209,17 +154,18 @@ int omap_plane_mode_set(struct drm_plane *plane,
 	win->src_w = src_w;
 	win->src_h = src_h;
 
-	if (fxn) {
-		/* omap_crtc should ensure that a new page flip
-		 * isn't permitted while there is one pending:
-		 */
-		BUG_ON(omap_plane->apply_done_cb.fxn);
+	return omap_plane_setup(omap_plane);
+}
 
-		omap_plane->apply_done_cb.fxn = fxn;
-		omap_plane->apply_done_cb.arg = arg;
-	}
+int omap_plane_set_enable(struct drm_plane *plane, bool enable)
+{
+	struct omap_plane *omap_plane = to_omap_plane(plane);
 
-	return omap_plane_apply(plane);
+	if (enable == omap_plane->enabled)
+		return 0;
+
+	omap_plane->enabled = enable;
+	return omap_plane_setup(omap_plane);
 }
 
 static int omap_plane_update(struct drm_plane *plane,
@@ -230,6 +176,8 @@ static int omap_plane_update(struct drm_plane *plane,
 		uint32_t src_w, uint32_t src_h)
 {
 	struct omap_plane *omap_plane = to_omap_plane(plane);
+	int ret;
+
 	omap_plane->enabled = true;
 
 	/* omap_plane_mode_set() takes adjusted src */
@@ -248,10 +196,14 @@ static int omap_plane_update(struct drm_plane *plane,
 	plane->crtc = crtc;
 
 	/* src values are in Q16 fixed point, convert to integer: */
-	return omap_plane_mode_set(plane, crtc, fb,
+	ret = omap_plane_mode_set(plane, crtc, fb,
 				  crtc_x, crtc_y, crtc_w, crtc_h,
-			src_x >> 16, src_y >> 16, src_w >> 16, src_h >> 16,
-			NULL, NULL);
+				  src_x >> 16, src_y >> 16,
+				  src_w >> 16, src_h >> 16);
+	if (ret < 0)
+		return ret;
+
+	return omap_crtc_flush(plane->crtc);
 }
 
 static int omap_plane_disable(struct drm_plane *plane)
@@ -262,7 +214,14 @@ static int omap_plane_disable(struct drm_plane *plane)
 	omap_plane->info.zorder = plane->type == DRM_PLANE_TYPE_PRIMARY
 				? 0 : omap_plane->id;
 
-	return omap_plane_set_enable(plane, false);
+	if (!omap_plane->enabled)
+		return 0;
+
+	/* Disabling a plane never fails. */
+	omap_plane->enabled = false;
+	omap_plane_setup(omap_plane);
+
+	return omap_crtc_flush(plane->crtc);
 }
 
 static void omap_plane_destroy(struct drm_plane *plane)
@@ -275,22 +234,9 @@ static void omap_plane_destroy(struct drm_plane *plane)
 
 	drm_plane_cleanup(plane);
 
-	drm_flip_work_cleanup(&omap_plane->unpin_work);
-
 	kfree(omap_plane);
 }
 
-int omap_plane_set_enable(struct drm_plane *plane, bool enable)
-{
-	struct omap_plane *omap_plane = to_omap_plane(plane);
-
-	if (enable == omap_plane->enabled)
-		return 0;
-
-	omap_plane->enabled = enable;
-	return omap_plane_apply(plane);
-}
-
 /* helper to install properties which are common to planes and crtcs */
 void omap_plane_install_properties(struct drm_plane *plane,
 		struct drm_mode_object *obj)
@@ -312,19 +258,30 @@ int omap_plane_set_property(struct drm_plane *plane,
 {
 	struct omap_plane *omap_plane = to_omap_plane(plane);
 	struct omap_drm_private *priv = plane->dev->dev_private;
-	int ret = -EINVAL;
+	int ret;
 
 	if (property == plane->dev->mode_config.rotation_property) {
 		DBG("%s: rotation: %02x", omap_plane->name, (uint32_t)val);
 		omap_plane->win.rotation = val;
-		ret = omap_plane_apply(plane);
 	} else if (property == priv->zorder_prop) {
 		DBG("%s: zorder: %02x", omap_plane->name, (uint32_t)val);
 		omap_plane->info.zorder = val;
-		ret = omap_plane_apply(plane);
+	} else {
+		return -EINVAL;
 	}
 
+	/*
+	 * We're done if the plane is disabled, properties will be applied the
+	 * next time it becomes enabled.
+	 */
+	if (!omap_plane->enabled)
+		return 0;
+
+	ret = omap_plane_setup(omap_plane);
+	if (ret < 0)
 		return ret;
+
+	return omap_crtc_flush(plane->crtc);
 }
 
 static const struct drm_plane_funcs omap_plane_funcs = {
@@ -372,9 +329,6 @@ struct drm_plane *omap_plane_init(struct drm_device *dev,
 	if (!omap_plane)
 		return ERR_PTR(-ENOMEM);
 
-	drm_flip_work_init(&omap_plane->unpin_work,
-			"unpin", omap_plane_unpin_worker);
-
 	omap_plane->nformats = omap_framebuffer_get_formats(
 			omap_plane->formats, ARRAY_SIZE(omap_plane->formats),
 			dss_feat_get_supported_color_modes(id));
@@ -383,9 +337,6 @@ struct drm_plane *omap_plane_init(struct drm_device *dev,
 
 	plane = &omap_plane->base;
 
-	omap_plane->apply.pre_apply  = omap_plane_pre_apply;
-	omap_plane->apply.post_apply = omap_plane_post_apply;
-
 	omap_plane->error_irq.irqmask = error_irqs[id];
 	omap_plane->error_irq.irq = omap_plane_error_irq;
 	omap_irq_register(dev, &omap_plane->error_irq);