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Commit 16223eff authored by Adrian Salido-Moreno's avatar Adrian Salido-Moreno
Browse files

msm: mdss: refactor ping pong completion logic 



Replace completion structures with waitq and track the completion of
ping pong transfer with a single kickoff count variable. This prevents
race conditions when using completion structure and provides a cleaner
way to identify whether wait is required.

CRs-Fixed: 720541
Change-Id: Iebb8077d520649db427470fc4963d892967a920c
Signed-off-by: default avatarAdrian Salido-Moreno <adrianm@codeaurora.org>
parent 169417fe

drivers/video/msm/mdss/mdss_mdp_intf_cmd.c

+52 −61
Original line number Diff line number Diff line
@@ -34,8 +34,8 @@ struct mdss_mdp_cmd_ctx { 
	struct mdss_mdp_ctl *ctl;

	u32 pp_num;

	u8 ref_cnt;

	struct completion pp_comp;

	struct completion stop_comp;

	wait_queue_head_t pp_waitq;

	struct list_head vsync_handlers;

	int panel_power_state;

	atomic_t koff_cnt;
@@ -332,7 +332,6 @@ static void mdss_mdp_cmd_underflow_recovery(void *data) 
		atomic_dec(&ctx->koff_cnt);

		mdss_mdp_irq_disable_nosync(MDSS_MDP_IRQ_PING_PONG_COMP,

						ctx->pp_num);

		complete_all(&ctx->pp_comp);

	}

	spin_unlock_irqrestore(&ctx->koff_lock, flags);

}
@@ -361,22 +360,21 @@ static void mdss_mdp_cmd_pingpong_done(void *arg) 


	spin_lock(&ctx->koff_lock);

	mdss_mdp_irq_disable_nosync(MDSS_MDP_IRQ_PING_PONG_COMP, ctx->pp_num);

	complete_all(&ctx->pp_comp);

	MDSS_XLOG(ctl->num, atomic_read(&ctx->koff_cnt), ctx->clk_enabled,

					ctx->rdptr_enabled);



	if (atomic_read(&ctx->koff_cnt)) {

		if (atomic_dec_return(&ctx->koff_cnt)) {

	if (atomic_add_unless(&ctx->koff_cnt, -1, 0)) {

		if (atomic_read(&ctx->koff_cnt))

			pr_err("%s: too many kickoffs=%d!\n", __func__,

			       atomic_read(&ctx->koff_cnt));

			atomic_set(&ctx->koff_cnt, 0);

		}

		if (mdss_mdp_cmd_do_notifier(ctx)) {

			atomic_inc(&ctx->pp_done_cnt);

			schedule_work(&ctx->pp_done_work);

		}

	} else

		wake_up_all(&ctx->pp_waitq);

	} else {

		pr_err("%s: should not have pingpong interrupt!\n", __func__);

	}



	trace_mdp_cmd_pingpong_done(ctl, ctx->pp_num,

					atomic_read(&ctx->koff_cnt));
@@ -516,7 +514,6 @@ static int mdss_mdp_cmd_wait4pingpong(struct mdss_mdp_ctl *ctl, void *arg) 
	struct mdss_mdp_cmd_ctx *ctx;

	struct mdss_panel_data *pdata;

	unsigned long flags;

	int need_wait = 0;

	int rc = 0;



	ctx = (struct mdss_mdp_cmd_ctx *) ctl->priv_data;
@@ -527,11 +524,6 @@ static int mdss_mdp_cmd_wait4pingpong(struct mdss_mdp_ctl *ctl, void *arg) 


	pdata = ctl->panel_data;



	spin_lock_irqsave(&ctx->koff_lock, flags);

	if (atomic_read(&ctx->koff_cnt) > 0)

		need_wait = 1;

	spin_unlock_irqrestore(&ctx->koff_lock, flags);



	ctl->roi_bkup.w = ctl->width;

	ctl->roi_bkup.h = ctl->height;
@@ -539,12 +531,12 @@ static int mdss_mdp_cmd_wait4pingpong(struct mdss_mdp_ctl *ctl, void *arg) 
			ctx->rdptr_enabled, ctl->roi_bkup.w,

			ctl->roi_bkup.h);



	pr_debug("%s: need_wait=%d  intf_num=%d ctx=%p\n",

			__func__, need_wait, ctl->intf_num, ctx);

	pr_debug("%s: intf_num=%d ctx=%p koff_cnt=%d\n", __func__,

			ctl->intf_num, ctx, atomic_read(&ctx->koff_cnt));



	if (need_wait) {

		rc = wait_for_completion_timeout(

				&ctx->pp_comp, KOFF_TIMEOUT);

	rc = wait_event_timeout(ctx->pp_waitq,

			atomic_read(&ctx->koff_cnt) == 0,

			KOFF_TIMEOUT);



	trace_mdp_cmd_wait_pingpong(ctl->num,

				atomic_read(&ctx->koff_cnt));
@@ -566,7 +558,7 @@ static int mdss_mdp_cmd_wait4pingpong(struct mdss_mdp_ctl *ctl, void *arg) 
			rc = 1;

		}



			rc = try_wait_for_completion(&ctx->pp_comp);

		rc = atomic_read(&ctx->koff_cnt) == 0;

	}



	if (rc <= 0) {
@@ -579,14 +571,19 @@ static int mdss_mdp_cmd_wait4pingpong(struct mdss_mdp_ctl *ctl, void *arg) 
		ctx->pp_timeout_report_cnt++;

		rc = -EPERM;

		mdss_mdp_ctl_notify(ctl, MDP_NOTIFY_FRAME_TIMEOUT);

		atomic_add_unless(&ctx->koff_cnt, -1, 0);

	} else {

		rc = 0;

		ctx->pp_timeout_report_cnt = 0;

	}

	}



	/* signal any pending ping pong done events */

	while (atomic_add_unless(&ctx->pp_done_cnt, -1, 0))

		mdss_mdp_ctl_notify(ctx->ctl, MDP_NOTIFY_FRAME_DONE);



	MDSS_XLOG(ctl->num, atomic_read(&ctx->koff_cnt), ctx->clk_enabled,

			ctx->rdptr_enabled, rc);



	return rc;

}
@@ -668,7 +665,6 @@ int mdss_mdp_cmd_kickoff(struct mdss_mdp_ctl *ctl, void *arg) 
{

	struct mdss_mdp_ctl *sctl = NULL;

	struct mdss_mdp_cmd_ctx *ctx, *sctx = NULL;

	unsigned long flags;

	int rc;



	ctx = (struct mdss_mdp_cmd_ctx *) ctl->priv_data;
@@ -713,14 +709,9 @@ int mdss_mdp_cmd_kickoff(struct mdss_mdp_ctl *ctl, void *arg) 
	MDSS_XLOG(ctl->num, ctl->roi.x, ctl->roi.y, ctl->roi.w,

						ctl->roi.h);



	spin_lock_irqsave(&ctx->koff_lock, flags);

	atomic_inc(&ctx->koff_cnt);

	INIT_COMPLETION(ctx->pp_comp);

	if (sctx) {

	if (sctx)

		atomic_inc(&sctx->koff_cnt);

		INIT_COMPLETION(sctx->pp_comp);

	}

	spin_unlock_irqrestore(&ctx->koff_lock, flags);



	trace_mdp_cmd_kickoff(ctl->num, atomic_read(&ctx->koff_cnt));
@@ -952,7 +943,7 @@ static int mdss_mdp_cmd_intfs_setup(struct mdss_mdp_ctl *ctl, 
	ctx->ctl = ctl;

	ctx->pp_num = (is_split_dst(ctl->mfd) ? session : mixer->num);

	ctx->pp_timeout_report_cnt = 0;

	init_completion(&ctx->pp_comp);

	init_waitqueue_head(&ctx->pp_waitq);

	init_completion(&ctx->stop_comp);

	spin_lock_init(&ctx->clk_lock);

	spin_lock_init(&ctx->koff_lock);