tree 7610e38b15129e8017dbf60dbd769909da4e0027
parent bbbc08a154a1750371f8347a5353819551d11abb
author Alexander Shishkin <alexander.shishkin@linux.intel.com> 1561639907 +0300
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1562168757 +0200

intel_th: msu: Start read iterator from a non-empty window

In multi-window mode, the read iterator is supposed to start from the
window with the oldest data, which is, chronologically, the next window
after the one with the newest data. This, however, fails to take into
account the potentially empty windows, so in short trace sessions it's
possible to have a lot of zeroes read from the character device first.

Fix this by skipping over the empty windows in initialization of the
read iterator.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190627125152.54905-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>