diff options
| author | Mathieu Poirier <mathieu.poirier@linaro.org> | 2019-05-09 15:39:50 -0600 |
|---|---|---|
| committer | Mathieu Poirier <mathieu.poirier@linaro.org> | 2019-05-09 15:53:50 -0600 |
| commit | f2d37b111408077185b48f6f827d1f151b06025b (patch) | |
| tree | 2a8a53a939418dd49ece2eeaf1937e1e943fb859 | |
| parent | 9b384b88148d3e489d2779bf165b4b3e05e6df8c (diff) | |
coresight: tmc-etf: Properly set AUX buffer head in snapshot mode
Unify amongst sink drivers how the AUX ring buffer head is communicated
to user space. That way the same algorithm in cs_etm_find_snapshot()
can be used to determine where the latest data is and how much of it
to access.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-etf.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 2527b5d3b65e..d026bd04a6af 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -542,11 +542,15 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, } } - /* In snapshot mode we have to update the head */ - if (buf->snapshot) { - handle->head = (cur * PAGE_SIZE) + offset; - to_read = buf->nr_pages << PAGE_SHIFT; - } + /* + * In snapshot mode we simply increment the head by the number of byte + * that were written. User space function cs_etm_find_snapshot() will + * figure out how many bytes to get from the AUX buffer based on the + * position of the head. + */ + if (buf->snapshot) + handle->head += to_read; + CS_LOCK(drvdata->base); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); |