The read pointer (read_ptr) needs to be adjusted only if its value has gone beyond the length of the memory buffer.
Reported-by: Suzuki K Poulose <suzuki.poul...@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poir...@linaro.org> --- drivers/hwtracing/coresight/coresight-etb10.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index 586c98fbdb03..1e4031ee8969 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -428,7 +428,8 @@ static void etb_update_buffer(struct coresight_device *csdev, read_ptr = (write_ptr + drvdata->buffer_depth) - to_read / ETB_FRAME_SIZE_WORDS; /* Wrap around if need be*/ - read_ptr &= ~(drvdata->buffer_depth - 1); + if (read_ptr > (drvdata->buffer_depth - 1)) + read_ptr -= drvdata->buffer_depth; /* let the decoder know we've skipped ahead */ local_inc(&buf->lost); } -- 2.5.0