intel_th: msu: Preserve pre-existing buffer configuration

The MSU configuration registers may contain buffer address/size set by
the BIOS or an external hardware debugger, which may want to take over
tracing from the driver when the driver is not actively tracing.

Preserve these settings when not actively tracing.

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/20190705141425.19894-6-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexander Shishkin 2019-07-05 17:14:25 +03:00 • committed by Greg Kroah-Hartman
commit 092f47c383