coresight: Properly address errors in sink::disable() functions

When disabling a sink the reference counter ensures the operation goes
through if nobody else is using it.  As such if drvdata::mode is already
set do CS_MODE_DISABLED, it is an error and should be reported as such.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-etb10.c

@@ -333,11 +333,10 @@ static int etb_disable(struct coresight_device *csdev)
 		return -EBUSY;
 	}
 
-	/* Disable the ETB only if it needs to */
-	if (drvdata->mode != CS_MODE_DISABLED) {
+	/* Complain if we (somehow) got out of sync */
+	WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
 	etb_disable_hw(drvdata);
 	drvdata->mode = CS_MODE_DISABLED;
-	}
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
 	dev_dbg(drvdata->dev, "ETB disabled\n");

drivers/hwtracing/coresight/coresight-tmc-etf.c

@@ -297,11 +297,10 @@ static int tmc_disable_etf_sink(struct coresight_device *csdev)
 		return -EBUSY;
 	}
 
-	/* Disable the TMC only if it needs to */
-	if (drvdata->mode != CS_MODE_DISABLED) {
+	/* Complain if we (somehow) got out of sync */
+	WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
 	tmc_etb_disable_hw(drvdata);
 	drvdata->mode = CS_MODE_DISABLED;
-	}
 
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 

drivers/hwtracing/coresight/coresight-tmc-etr.c

@@ -1417,11 +1417,10 @@ static int tmc_disable_etr_sink(struct coresight_device *csdev)
 		return -EBUSY;
 	}
 
-	/* Disable the TMC only if it needs to */
-	if (drvdata->mode != CS_MODE_DISABLED) {
+	/* Complain if we (somehow) got out of sync */
+	WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
 	tmc_etr_disable_hw(drvdata);
 	drvdata->mode = CS_MODE_DISABLED;
-	}
 
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);