drm/msm/mdp5: Wait for PP_DONE irq for command mode CRTC atomic commit

CRTCs in DSI command mode data path should wait for pingpong done,
instead of vblank, to finish atomic commit.

This change is to enable PP_DONE irq on command mode CRTCs and wait for
this irq happens before atomic commit completion.

Signed-off-by: Hai Li <hali@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/mdp/mdp5/mdp5_cmd_encoder.c

@@ -216,16 +216,12 @@ static void mdp5_cmd_encoder_mode_set(struct drm_encoder *encoder,
 static void mdp5_cmd_encoder_disable(struct drm_encoder *encoder)
 {
 	struct mdp5_cmd_encoder *mdp5_cmd_enc = to_mdp5_cmd_encoder(encoder);
-	struct mdp5_kms *mdp5_kms = get_kms(encoder);
 	struct mdp5_ctl *ctl = mdp5_crtc_get_ctl(encoder->crtc);
 	struct mdp5_interface *intf = &mdp5_cmd_enc->intf;
-	int lm = mdp5_crtc_get_lm(encoder->crtc);
 
 	if (WARN_ON(!mdp5_cmd_enc->enabled))
 		return;
 
-	/* Wait for the last frame done */
-	mdp_irq_wait(&mdp5_kms->base, lm2ppdone(lm));
 	pingpong_tearcheck_disable(encoder);
 
 	mdp5_ctl_set_encoder_state(ctl, false);

drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014-2015 The Linux Foundation. All rights reserved.
  * Copyright (C) 2013 Red Hat
  * Author: Rob Clark <robdclark@gmail.com>
  *
@@ -60,6 +60,11 @@ struct mdp5_crtc {
 
 	struct mdp_irq vblank;
 	struct mdp_irq err;
+	struct mdp_irq pp_done;
+
+	struct completion pp_completion;
+
+	bool cmd_mode;
 
 	struct {
 		/* protect REG_MDP5_LM_CURSOR* registers and cursor scanout_bo*/
@@ -87,6 +92,12 @@ static void request_pending(struct drm_crtc *crtc, uint32_t pending)
 	mdp_irq_register(&get_kms(crtc)->base, &mdp5_crtc->vblank);
 }
 
+static void request_pp_done_pending(struct drm_crtc *crtc)
+{
+	struct mdp5_crtc *mdp5_crtc = to_mdp5_crtc(crtc);
+	reinit_completion(&mdp5_crtc->pp_completion);
+}
+
 static u32 crtc_flush(struct drm_crtc *crtc, u32 flush_mask)
 {
 	struct mdp5_crtc *mdp5_crtc = to_mdp5_crtc(crtc);
@@ -281,6 +292,9 @@ static void mdp5_crtc_disable(struct drm_crtc *crtc)
 	if (WARN_ON(!mdp5_crtc->enabled))
 		return;
 
+	if (mdp5_crtc->cmd_mode)
+		mdp_irq_unregister(&mdp5_kms->base, &mdp5_crtc->pp_done);
+
 	mdp_irq_unregister(&mdp5_kms->base, &mdp5_crtc->err);
 	mdp5_disable(mdp5_kms);
 
@@ -300,6 +314,9 @@ static void mdp5_crtc_enable(struct drm_crtc *crtc)
 	mdp5_enable(mdp5_kms);
 	mdp_irq_register(&mdp5_kms->base, &mdp5_crtc->err);
 
+	if (mdp5_crtc->cmd_mode)
+		mdp_irq_register(&mdp5_kms->base, &mdp5_crtc->pp_done);
+
 	mdp5_crtc->enabled = true;
 }
 
@@ -401,6 +418,15 @@ static void mdp5_crtc_atomic_flush(struct drm_crtc *crtc)
 
 	blend_setup(crtc);
 
+	/* PP_DONE irq is only used by command mode for now.
+	 * It is better to request pending before FLUSH and START trigger
+	 * to make sure no pp_done irq missed.
+	 * This is safe because no pp_done will happen before SW trigger
+	 * in command mode.
+	 */
+	if (mdp5_crtc->cmd_mode)
+		request_pp_done_pending(crtc);
+
 	mdp5_crtc->flushed_mask = crtc_flush_all(crtc);
 
 	request_pending(crtc, PENDING_FLIP);
@@ -607,6 +633,26 @@ static void mdp5_crtc_err_irq(struct mdp_irq *irq, uint32_t irqstatus)
 	DBG("%s: error: %08x", mdp5_crtc->name, irqstatus);
 }
 
+static void mdp5_crtc_pp_done_irq(struct mdp_irq *irq, uint32_t irqstatus)
+{
+	struct mdp5_crtc *mdp5_crtc = container_of(irq, struct mdp5_crtc,
+								pp_done);
+
+	complete(&mdp5_crtc->pp_completion);
+}
+
+static void mdp5_crtc_wait_for_pp_done(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct mdp5_crtc *mdp5_crtc = to_mdp5_crtc(crtc);
+	int ret;
+
+	ret = wait_for_completion_timeout(&mdp5_crtc->pp_completion,
+						msecs_to_jiffies(50));
+	if (ret == 0)
+		dev_warn(dev->dev, "pp done time out, lm=%d\n", mdp5_crtc->lm);
+}
+
 static void mdp5_crtc_wait_for_flush_done(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
@@ -654,16 +700,18 @@ void mdp5_crtc_set_intf(struct drm_crtc *crtc, struct mdp5_interface *intf)
 
 	/* now that we know what irq's we want: */
 	mdp5_crtc->err.irqmask = intf2err(intf->num);
-
-	/* Register command mode Pingpong done as vblank for now,
-	 * so that atomic commit should wait for it to finish.
-	 * Ideally, in the future, we should take rd_ptr done as vblank,
-	 * and let atomic commit wait for pingpong done for commond mode.
-	 */
-	if (intf->mode == MDP5_INTF_DSI_MODE_COMMAND)
-		mdp5_crtc->vblank.irqmask = lm2ppdone(lm);
-	else
-		mdp5_crtc->vblank.irqmask = intf2vblank(lm, intf);
+	mdp5_crtc->vblank.irqmask = intf2vblank(lm, intf);
+
+	if ((intf->type == INTF_DSI) &&
+		(intf->mode == MDP5_INTF_DSI_MODE_COMMAND)) {
+		mdp5_crtc->pp_done.irqmask = lm2ppdone(lm);
+		mdp5_crtc->pp_done.irq = mdp5_crtc_pp_done_irq;
+		mdp5_crtc->cmd_mode = true;
+	} else {
+		mdp5_crtc->pp_done.irqmask = 0;
+		mdp5_crtc->pp_done.irq = NULL;
+		mdp5_crtc->cmd_mode = false;
+	}
 
 	mdp_irq_update(&mdp5_kms->base);
 
@@ -684,11 +732,12 @@ struct mdp5_ctl *mdp5_crtc_get_ctl(struct drm_crtc *crtc)
 
 void mdp5_crtc_wait_for_commit_done(struct drm_crtc *crtc)
 {
-	/* wait_for_flush_done is the only case for now.
-	 * Later we will have command mode CRTC to wait for
-	 * other event.
-	 */
-	mdp5_crtc_wait_for_flush_done(crtc);
+	struct mdp5_crtc *mdp5_crtc = to_mdp5_crtc(crtc);
+
+	if (mdp5_crtc->cmd_mode)
+		mdp5_crtc_wait_for_pp_done(crtc);
+	else
+		mdp5_crtc_wait_for_flush_done(crtc);
 }
 
 /* initialize crtc */
@@ -709,6 +758,7 @@ struct drm_crtc *mdp5_crtc_init(struct drm_device *dev,
 
 	spin_lock_init(&mdp5_crtc->lm_lock);
 	spin_lock_init(&mdp5_crtc->cursor.lock);
+	init_completion(&mdp5_crtc->pp_completion);
 
 	mdp5_crtc->vblank.irq = mdp5_crtc_vblank_irq;
 	mdp5_crtc->err.irq = mdp5_crtc_err_irq;