[PATCH 1/4] coresight: tmc-etr: Advance buffer pointer in sync buffer.

Daniel Kiss
2021-04-21T12:07:32Z

With polling the sync could called multiple times in a row. Without this
change the data will be overwritten at the beginning of the buffer.

Signed-off-by: Daniel Kiss <daniel.kiss@arm.com>
Signed-off-by: Branislav Rankov <Branislav.Rankov@arm.com>
---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index ea5027e397d02..dd19d1d1c3b38 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1442,7 +1442,7 @@ static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,
{
long bytes;
long pg_idx, pg_offset;
- unsigned long head = etr_perf->head;
+ unsigned long head;
char **dst_pages, *src_buf;
struct etr_buf *etr_buf = etr_perf->etr_buf;

@@ -1465,7 +1465,7 @@ static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,
bytes = tmc_etr_buf_get_data(etr_buf, src_offset, to_copy,
&src_buf);
if (WARN_ON_ONCE(bytes <= 0))
- break;
+ return;
bytes = min(bytes, (long)(PAGE_SIZE - pg_offset));

memcpy(dst_pages[pg_idx] + pg_offset, src_buf, bytes);
@@ -1483,6 +1483,7 @@ static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,
/* Move source pointers */
src_offset += bytes;
}
+ etr_perf->head = (pg_idx << PAGE_SHIFT) + pg_offset;
}

/*
--
2.25.1