From ac9aa295f7a89d38656739628796f086f0b160e2 Mon Sep 17 00:00:00 2001
From: Xu Yang <xu.yang_2@nxp.com>
Date: Wed, 29 May 2024 16:03:55 +0800
Subject: [PATCH] perf: imx_perf: fix counter start and config sequence
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.
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Fixes: 55691f99d417 ("drivers/perf: imx_ddr: Add support for NXP i.MX9 SoC DDRC PMU driver")
cc: stable@vger.kernel.org
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240529080358.703784-5-xu.yang_2@nxp.com
Signed-off-by: Will Deacon <will@kernel.org>
---
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 5433c52a98729..7b43b54920da0 100644
--- a/drivers/perf/fsl_imx9_ddr_perf.c
+++ b/drivers/perf/fsl_imx9_ddr_perf.c
@@ -541,12 +541,12 @@ 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;
}
--
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