[PATCH v3 07/20] coresight: Properly address errors in sink::disable() functions

[Mathieu Poirier]

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.poir...@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
 drivers/hwtracing/coresight/coresight-etb10.c   | 9 ++++-----
 drivers/hwtracing/coresight/coresight-tmc-etf.c | 9 ++++-----
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 9 ++++-----
 3 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etb10.c 
b/drivers/hwtracing/coresight/coresight-etb10.c
index 5af50a852e87..52b7d95ab498 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -341,11 +341,10 @@ static int etb_disable(struct coresight_device *csdev)
                return -EBUSY;
        }
 
-       /* Disable the ETB only if it needs to */
-       if (drvdata->mode != CS_MODE_DISABLED) {
-               etb_disable_hw(drvdata);
-               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");
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c 
b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index d50a608a60f1..30f868676540 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/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) {
-               tmc_etb_disable_hw(drvdata);
-               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);
 
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c 
b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index f90bca971367..86e748d09dc3 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1416,11 +1416,10 @@ 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) {
-               tmc_etr_disable_hw(drvdata);
-               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);
 
-- 
2.17.1