linux-kernel - [PATCH v2 06/27] coresight: tmc etr: Disallow perf mode temporarily

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Date:   Tue,  1 May 2018 10:10:36 +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, mark.rutland@....com,
        will.deacon@....com, robin.murphy@....com, sudeep.holla@....com,
        frowand.list@...il.com, robh@...nel.org, john.horley@....com,
        Suzuki K Poulose <suzuki.poulose@....com>
Subject: [PATCH v2 06/27] coresight: tmc etr: Disallow perf mode temporarily

We don't support ETR in perf mode yet. Temporarily fail the
operation until we add proper support.

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 9b0c620..bff46f2 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -218,32 +218,8 @@ 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