[PATCH v6 5/7] perf: imx_perf: fix counter start and config sequence

From: Xu Yang <xu.yang_2@nxp.com>
To: Frank.li@nxp.com, will@kernel.org, mark.rutland@arm.com,
	robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
	conor+dt@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de,
	kernel@pengutronix.de, festevam@gmail.com,
	john.g.garry@oracle.com, jolsa@kernel.org, namhyung@kernel.org,
	irogers@google.com
Cc: mike.leach@linaro.org, peterz@infradead.org, mingo@redhat.com,
	acme@kernel.org, alexander.shishkin@linux.intel.com,
	adrian.hunter@intel.com, linux-arm-kernel@lists.infradead.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-perf-users@vger.kernel.org, imx@lists.linux.dev
Subject: [PATCH v6 5/7] perf: imx_perf: fix counter start and config sequence
Date: Thu,  7 Mar 2024 17:57:28 +0800	[thread overview]
Message-ID: <20240307095730.3792680-5-xu.yang_2@nxp.com> (raw)
In-Reply-To: <20240307095730.3792680-1-xu.yang_2@nxp.com>

In current driver, the counter will start firstly and then be configured.
This sequence is not correct for AXI filter events since the correct
AXI_MASK and AXI_ID are not set yet. Then the results may be inaccurate.

Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

---
Changes in v5:
 - new patch
Changes in v6:
 - no changes
---
 drivers/perf/fsl_imx9_ddr_perf.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/perf/fsl_imx9_ddr_perf.c b/drivers/perf/fsl_imx9_ddr_perf.c
index 4e8a3a4349c5..52234b97d0cb 100644
--- a/drivers/perf/fsl_imx9_ddr_perf.c
+++ b/drivers/perf/fsl_imx9_ddr_perf.c
@@ -543,12 +543,12 @@ static int ddr_perf_event_add(struct perf_event *event, int flags)
 	hwc->idx = counter;
 	hwc->state |= PERF_HES_STOPPED;
 
-	if (flags & PERF_EF_START)
-		ddr_perf_event_start(event, flags);
-
 	/* read trans, write trans, read beat */
 	imx93_ddr_perf_monitor_config(pmu, event_id, counter, cfg1, cfg2);
 
+	if (flags & PERF_EF_START)
+		ddr_perf_event_start(event, flags);
+
 	return 0;
 }
 
-- 
2.34.1

