coresight: etb10: adjust read pointer only when needed

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.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathieu Poirier 2016-05-03 11:34:01 -06:00 committed by Greg Kroah-Hartman
parent dc2c4ef141
commit bedffda8ca

View file

@ -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);
}