msm: mdss: false ESD detections due to race condition

There is a race condition between ESD thread and commit thread
which causes false ESD detections. This change prevents the
condition.

Change-Id: I67a480f7251348fc86be01fe8d5414857f53bc75
Signed-off-by: Naseer Ahmed <naseer@codeaurora.org>

4 files changed, 15 insertions, 7 deletions

diff --git a/drivers/video/fbdev/msm/dsi_host_v2.c b/drivers/video/fbdev/msm/dsi_host_v2.c
index 9b4afb265b00..a8a6c2b7afac 100644
--- a/drivers/video/fbdev/msm/dsi_host_v2.c
+++ b/drivers/video/fbdev/msm/dsi_host_v2.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -1000,7 +1000,7 @@ int msm_dsi_cmdlist_commit(struct mdss_dsi_ctrl_pdata *ctrl, int from_mdp)
 
 	if (from_mdp)	/* from mdp kickoff */
 		mutex_lock(&ctrl->cmd_mutex);
-	req = mdss_dsi_cmdlist_get(ctrl);
+	req = mdss_dsi_cmdlist_get(ctrl, from_mdp);
 
 	if (!req) {
 		mutex_unlock(&ctrl->cmd_mutex);
diff --git a/drivers/video/fbdev/msm/mdss_dsi_cmd.c b/drivers/video/fbdev/msm/mdss_dsi_cmd.c
index 0e7de6654e25..d07b504ff302 100644
--- a/drivers/video/fbdev/msm/mdss_dsi_cmd.c
+++ b/drivers/video/fbdev/msm/mdss_dsi_cmd.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -724,7 +724,8 @@ void mdss_dsi_set_tear_off(struct mdss_dsi_ctrl_pdata *ctrl)
 /*
  * mdss_dsi_cmd_get: ctrl->cmd_mutex acquired by caller
  */
-struct dcs_cmd_req *mdss_dsi_cmdlist_get(struct mdss_dsi_ctrl_pdata *ctrl)
+struct dcs_cmd_req *mdss_dsi_cmdlist_get(struct mdss_dsi_ctrl_pdata *ctrl,
+				int from_mdp)
 {
 	struct dcs_cmd_list *clist;
 	struct dcs_cmd_req *req = NULL;
@@ -733,6 +734,12 @@ struct dcs_cmd_req *mdss_dsi_cmdlist_get(struct mdss_dsi_ctrl_pdata *ctrl)
 	clist = &ctrl->cmdlist;
 	if (clist->get != clist->put) {
 		req = &clist->list[clist->get];
+		/*dont let commit thread steal ESD thread's
+		command*/
+		if (from_mdp && (req->flags & CMD_REQ_COMMIT)) {
+			mutex_unlock(&ctrl->cmdlist_mutex);
+			return NULL;
+		}
 		clist->get++;
 		clist->get %= CMD_REQ_MAX;
 		clist->tot--;
diff --git a/drivers/video/fbdev/msm/mdss_dsi_cmd.h b/drivers/video/fbdev/msm/mdss_dsi_cmd.h
index d62711558cd8..0ca968a00460 100644
--- a/drivers/video/fbdev/msm/mdss_dsi_cmd.h
+++ b/drivers/video/fbdev/msm/mdss_dsi_cmd.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -133,7 +133,8 @@ int mdss_dsi_short_read2_resp(struct dsi_buf *rp);
 int mdss_dsi_long_read_resp(struct dsi_buf *rp);
 void mdss_dsi_set_tear_on(struct mdss_dsi_ctrl_pdata *ctrl);
 void mdss_dsi_set_tear_off(struct mdss_dsi_ctrl_pdata *ctrl);
-struct dcs_cmd_req *mdss_dsi_cmdlist_get(struct mdss_dsi_ctrl_pdata *ctrl);
+struct dcs_cmd_req *mdss_dsi_cmdlist_get(struct mdss_dsi_ctrl_pdata *ctrl,
+				int from_mdp);
 int mdss_dsi_cmdlist_put(struct mdss_dsi_ctrl_pdata *ctrl,
 				struct dcs_cmd_req *cmdreq);
 #endif
diff --git a/drivers/video/fbdev/msm/mdss_dsi_host.c b/drivers/video/fbdev/msm/mdss_dsi_host.c
index cc0cbea6fced..5f9c936b54ba 100644
--- a/drivers/video/fbdev/msm/mdss_dsi_host.c
+++ b/drivers/video/fbdev/msm/mdss_dsi_host.c
@@ -2403,7 +2403,7 @@ int mdss_dsi_cmdlist_commit(struct mdss_dsi_ctrl_pdata *ctrl, int from_mdp)
 			roi = &pinfo->roi;
 	}
 
-	req = mdss_dsi_cmdlist_get(ctrl);
+	req = mdss_dsi_cmdlist_get(ctrl, from_mdp);
 	if (req && from_mdp && ctrl->burst_mode_enabled) {
 		mutex_lock(&ctrl->cmd_mutex);
 		cmd_mutex_acquired = true;