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coresight: tmc-etr: Decouple buffer sync and barrier packet insertion 

If less space is available in the perf ring buffer than the ETR buffer,
barrier packets inserted in the trace stream by tmc_sync_etr_buf() are
skipped over when the head of the buffer is moved forward, resulting in
traces that can't be decoded.

This patch decouples the process of syncing ETR buffers and the addition
of barrier packets in order to perform the latter once the offset in the
trace buffer has been properly computed.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20190829202842.580-17-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathieu Poirier 2019-08-29 14:28:41 -06:00 committed by Greg Kroah-Hartman
parent 00bb485ce7
commit 3507d231a4
1 changed files with 12 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/hwtracing/coresight/coresight-tmc-etr.c
View File

@ -946,10 +946,6 @@ static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata)
WARN_ON(!etr_buf->ops || !etr_buf->ops->sync);
etr_buf->ops->sync(etr_buf, rrp, rwp);
/* Insert barrier packets at the beginning, if there was an overflow */
if (etr_buf->full)
tmc_etr_buf_insert_barrier_packet(etr_buf, etr_buf->offset);
}
static void __tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
@ -1086,6 +1082,13 @@ static void tmc_etr_sync_sysfs_buf(struct tmc_drvdata *drvdata)
drvdata->sysfs_buf = NULL;
} else {
tmc_sync_etr_buf(drvdata);
/*
* Insert barrier packets at the beginning, if there was
* an overflow.
*/
if (etr_buf->full)
tmc_etr_buf_insert_barrier_packet(etr_buf,
etr_buf->offset);
}
}
@ -1502,11 +1505,16 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
lost = etr_buf->full;
size = etr_buf->len;
if (!etr_perf->snapshot && size > handle->size) {
size = handle->size;
lost = true;
}
/* Insert barrier packets at the beginning, if there was an overflow */
if (lost)
tmc_etr_buf_insert_barrier_packet(etr_buf, etr_buf->offset);
tmc_etr_sync_perf_buffer(etr_perf, size);
/*
@ -1517,8 +1525,6 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
*/
if (etr_perf->snapshot)
handle->head += size;
lost |= etr_buf->full;
out:
/*
* Don't set the TRUNCATED flag in snapshot mode because 1) the