Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Mao Jinlong <quic_jinlmao@quicinc.com>
To:     Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>
CC:     Mao Jinlong <quic_jinlmao@quicinc.com>,
        <coresight@lists.linaro.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>,
        Tingwei <quic_tingweiz@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Tao Zhang <quic_taozha@quicinc.com>,
        Hao Zhang <quic_hazha@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>
Subject: [PATCH] coresight: cti: Add PM runtime call in enable_store
Date:   Sat, 24 Dec 2022 22:17:00 +0800
Message-ID: <20221224141700.20891-1-quic_jinlmao@quicinc.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

In commit 6746eae4bbad ("coresight: cti: Fix hang in cti_disable_hw()")
PM runtime calls are removed from cti_enable_hw/cti_disable_hw. When
enabling CTI by writing enable sysfs node, clock for accessing CTI
register won't be enabled. Device will crash due to register access
issue. Add PM runtime call in enable_store to fix this issue.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 drivers/hwtracing/coresight/coresight-cti-sysfs.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
index 6d59c815ecf5..b1ed424ae043 100644
--- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
@@ -108,10 +108,17 @@ static ssize_t enable_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	if (val)
+	if (val) {
+		ret = pm_runtime_resume_and_get(dev->parent);
+		if (ret)
+			return ret;
 		ret = cti_enable(drvdata->csdev);
-	else
+		if (ret)
+			pm_runtime_put(dev->parent);
+	} else {
 		ret = cti_disable(drvdata->csdev);
+		pm_runtime_put(dev->parent);
+	}
 	if (ret)
 		return ret;
 	return size;
-- 
2.17.1