On Tue, Dec 02, 2025 at 04:56:47PM +0000, Coresight ML wrote:
On Tue, Dec 02, 2025 at 12:05:52PM +0000, Suzuki K Poulose wrote:
On 01/12/2025 11:22, Leo Yan wrote:
The overwrite erratum occurs only on wrap events, so apply the extra wrap condition check in the workaround.
Signed-off-by: Leo Yan leo.yan@arm.com
drivers/hwtracing/coresight/coresight-trbe.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index e579ea98523c24d23a0cd265dcdd0a46b52b52da..2600af12a8fb94bb8c74efda2a101aacd01b0b34 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -714,7 +714,7 @@ static unsigned long trbe_get_trace_size(struct perf_output_handle *handle, * 64bytes. Thus we ignore the potential triggering of the erratum * on WRAP and limit the data to LIMIT. */
- if (wrap)
- if (wrap && trbe_may_overwrite_in_fill_mode(buf->cpudata)) write = get_trbe_limit_pointer();
This must be trbe_may_write_out_of_range() ?
SDEN (e.g., [1]) is ambiguous about how the write pointer acts for the out-of-range erratum.
Thought again, we should not worry about out-of-range case.
As the workaround always ensures sufficient space beyond the limit, the write pointer remains valid within the allocated buffer even if it is updated and crosses that limit.