linux-kernel - [PATCH v2 04/12] coresight: tmc-etr: Disallow perf mode

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Message-Id: <1527599737-28408-5-git-send-email-suzuki.poulose@arm.com>
Date:   Tue, 29 May 2018 14:15:29 +0100
From:   Suzuki K Poulose <suzuki.poulose@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, mathieu.poirier@...aro.org,
        mike.leach@...aro.org, robert.walker@....com,
        coresight@...ts.linaro.org, devicetree@...r.kernel.org,
        robh@...nel.org, frowand.list@...il.com,
        Suzuki K Poulose <suzuki.poulose@....com>
Subject: [PATCH v2 04/12] coresight: tmc-etr: Disallow perf mode

We don't support ETR in perf mode yet. So, don't
even try to enable the hardware, even by mistake.

Cc: Mathieu Poirier <mathieu.poirier@...aro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com>
---
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 28 ++-----------------------
 1 file changed, 2 insertions(+), 26 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 1de05c9..18c9a18 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -211,32 +211,8 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
 
 static int tmc_enable_etr_sink_perf(struct coresight_device *csdev)
 {
-	int ret = 0;
-	unsigned long flags;
-	struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
-
-	spin_lock_irqsave(&drvdata->spinlock, flags);
-	if (drvdata->reading) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	/*
-	 * In Perf mode there can be only one writer per sink.  There
-	 * is also no need to continue if the ETR is already operated
-	 * from sysFS.
-	 */
-	if (drvdata->mode != CS_MODE_DISABLED) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	drvdata->mode = CS_MODE_PERF;
-	tmc_etr_enable_hw(drvdata);
-out:
-	spin_unlock_irqrestore(&drvdata->spinlock, flags);
-
-	return ret;
+	/* We don't support perf mode yet ! */
+	return -EINVAL;
 }
 
 static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
-- 
2.7.4