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

[Daniel Kiss]

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 at arm.com>
Signed-off-by: Branislav Rankov <Branislav.Rankov at 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