From 86c45e0761e895ae622c22d5a0e619ae23c22f36 Mon Sep 17 00:00:00 2001
From: Ramprasad Katkam <katkam@codeaurora.org>
Date: Tue, 16 Oct 2018 19:31:51 +0530
Subject: [PATCH] soc: swr-mstr: Avoid race condition during device up

During device up call from platform driver, if master
is already up pm get_sync is currently skipped. However
pm suspend can get called after this check. Hence do a pm
get_sync even if master is already up to avoid race
condition.

Change-Id: I1779db3d65f58bda220d1ec07706e91745814c1f
Signed-off-by: Ramprasad Katkam <katkam@codeaurora.org>
---
 soc/swr-mstr-ctrl.c | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/soc/swr-mstr-ctrl.c b/soc/swr-mstr-ctrl.c
index 3d1b080b66..af5adac499 100644
--- a/soc/swr-mstr-ctrl.c
+++ b/soc/swr-mstr-ctrl.c
@@ -1191,6 +1191,7 @@ static int swrm_disconnect_port(struct swr_master *master,
 		if (!port_req) {
 			dev_err(&master->dev, "%s:port not enabled : port %d\n",
 					 __func__, portinfo->port_id[i]);
+			mutex_unlock(&swrm->mlock);
 			return -EINVAL;
 		}
 		port_req->req_ch &= ~portinfo->ch_en[i];
@@ -2108,29 +2109,20 @@ int swrm_wcd_notify(struct platform_device *pdev, u32 id, void *data)
 	case SWR_DEVICE_UP:
 		dev_dbg(swrm->dev, "%s: swr master up called\n", __func__);
 		mutex_lock(&swrm->mlock);
+		pm_runtime_mark_last_busy(&pdev->dev);
+		pm_runtime_get_sync(&pdev->dev);
 		mutex_lock(&swrm->reslock);
-		if (swrm->state == SWR_MSTR_UP) {
-			dev_dbg(swrm->dev, "%s: SWR master is already UP: %d\n",
-				__func__, swrm->state);
-			list_for_each_entry(swr_dev, &mstr->devices, dev_list)
-				swr_reset_device(swr_dev);
-		} else {
-			pm_runtime_mark_last_busy(&pdev->dev);
-			mutex_unlock(&swrm->reslock);
-			pm_runtime_get_sync(&pdev->dev);
-			mutex_lock(&swrm->reslock);
-			list_for_each_entry(swr_dev, &mstr->devices, dev_list) {
-				ret = swr_reset_device(swr_dev);
-				if (ret) {
-					dev_err(swrm->dev,
-						"%s: failed to reset swr device %d\n",
-						__func__, swr_dev->dev_num);
-					swrm_clk_request(swrm, false);
-				}
+		list_for_each_entry(swr_dev, &mstr->devices, dev_list) {
+			ret = swr_reset_device(swr_dev);
+			if (ret) {
+				dev_err(swrm->dev,
+					"%s: failed to reset swr device %d\n",
+					__func__, swr_dev->dev_num);
+				swrm_clk_request(swrm, false);
 			}
-			pm_runtime_mark_last_busy(&pdev->dev);
-			pm_runtime_put_autosuspend(&pdev->dev);
 		}
+		pm_runtime_mark_last_busy(&pdev->dev);
+		pm_runtime_put_autosuspend(&pdev->dev);
 		mutex_unlock(&swrm->reslock);
 		mutex_unlock(&swrm->mlock);
 		break;