[PATCH] coresight: tmc-etr: Remove perf_data check.

[Yabin Cui]

When tracing etm data of multiple threads on multiple cpus through
perf interface, each cpu has a unique etr_perf_buffer while sharing
the same etr device. There is no guarantee that the last cpu starts
etm tracing also stops last. So the perf_data check is no longer valid.

Signed-off-by: Yabin Cui <yab...@google.com>
---
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 9 ---------
 drivers/hwtracing/coresight/coresight-tmc.h     | 2 --
 2 files changed, 11 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c 
b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 17006705287a..0418440e0141 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1484,20 +1484,12 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
                goto out;
        }
 
-       if (WARN_ON(drvdata->perf_data != etr_perf)) {
-               lost = true;
-               spin_unlock_irqrestore(&drvdata->spinlock, flags);
-               goto out;
-       }
-
        CS_UNLOCK(drvdata->base);
 
        tmc_flush_and_stop(drvdata);
        tmc_sync_etr_buf(drvdata);
 
        CS_LOCK(drvdata->base);
-       /* Reset perf specific data */
-       drvdata->perf_data = NULL;
        spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
        size = etr_buf->len;
@@ -1556,7 +1548,6 @@ static int tmc_enable_etr_sink_perf(struct 
coresight_device *csdev, void *data)
        }
 
        etr_perf->head = PERF_IDX2OFF(handle->head, etr_perf);
-       drvdata->perf_data = etr_perf;
 
        /*
         * No HW configuration is needed if the sink is already in
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h 
b/drivers/hwtracing/coresight/coresight-tmc.h
index 1ed50411cc3c..3881a9ee565a 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -178,7 +178,6 @@ struct etr_buf {
  *             device configuration register (DEVID)
  * @idr:       Holds etr_bufs allocated for this ETR.
  * @idr_mutex: Access serialisation for idr.
- * @perf_data: PERF buffer for ETR.
  * @sysfs_data:        SYSFS buffer for ETR.
  */
 struct tmc_drvdata {
@@ -202,7 +201,6 @@ struct tmc_drvdata {
        struct idr              idr;
        struct mutex            idr_mutex;
        struct etr_buf          *sysfs_buf;
-       void                    *perf_data;
 };
 
 struct etr_buf_operations {
-- 
2.22.0.770.g0f2c4a37fd-goog