[PATCH 4.9 078/101] perf intel-pt: Fix MTC timing after overflow

From: Greg Kroah-Hartman
Date: Sun Jul 01 2018 - 12:28:52 EST

4.9-stable review patch. If anyone has any objections, please let me know.


From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

commit dd27b87ab5fcf3ea1c060b5e3ab5d31cc78e9f4c upstream.

On some platforms, overflows will clear before MTC wraparound, and there
is no following TSC/TMA packet. In that case the previous TMA is valid.
Since there will be a valid TMA either way, stop setting 'have_tma' to
false upon overflow.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1527762225-26024-4-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 1 -
1 file changed, 1 deletion(-)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -1298,7 +1298,6 @@ static int intel_pt_overflow(struct inte
intel_pt_log("ERROR: Buffer overflow\n");
- decoder->have_tma = false;
decoder->cbr = 0;
decoder->timestamp_insn_cnt = 0;
decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;