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From: Yang Jihong <yangjihong1@huawei.com>
To: <yangyicong@hisilicon.com>, <jonathan.cameron@huawei.com>,
	<alexander.shishkin@linux.intel.com>, <mathieu.poirier@linaro.org>,
	<john.garry@huawei.com>, <linux-kernel@vger.kernel.org>
CC: <suzuki.poulose@arm.com>, <yangjihong1@huawei.com>,
	<wangkefeng.wang@huawei.com>, <yangyicong@huawei.com>
Subject: [PATCH v2] hwtracing: hisi_ptt: Move type check to the beginning of hisi_ptt_pmu_event_init()
Date: Mon, 8 Jan 2024 12:19:06 +0000
Message-ID: <20240108121906.3514820-1-yangjihong1@huawei.com>
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When perf_init_event() calls perf_try_init_event() to init pmu driver,
searches for the next pmu driver only when the return value is -ENOENT.
Therefore, hisi_ptt_pmu_event_init() needs to check the type at the
beginning of the function.
Otherwise, in the case of perf-task mode, perf_try_init_event() returns
-EOPNOTSUPP and skips subsequent pmu drivers, causes perf_init_event() to
fail.

Fixes: ff0de066b463 ("hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
---

Changes since v1:
 - Add fixes tag.

 drivers/hwtracing/ptt/hisi_ptt.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
index a991ecb7515a..24a1f7797aeb 100644
--- a/drivers/hwtracing/ptt/hisi_ptt.c
+++ b/drivers/hwtracing/ptt/hisi_ptt.c
@@ -995,6 +995,9 @@ static int hisi_ptt_pmu_event_init(struct perf_event *event)
 	int ret;
 	u32 val;
 
+	if (event->attr.type != hisi_ptt->hisi_ptt_pmu.type)
+		return -ENOENT;
+
 	if (event->cpu < 0) {
 		dev_dbg(event->pmu->dev, "Per-task mode not supported\n");
 		return -EOPNOTSUPP;
@@ -1003,9 +1006,6 @@ static int hisi_ptt_pmu_event_init(struct perf_event *event)
 	if (event->attach_state & PERF_ATTACH_TASK)
 		return -EOPNOTSUPP;
 
-	if (event->attr.type != hisi_ptt->hisi_ptt_pmu.type)
-		return -ENOENT;
-
 	ret = hisi_ptt_trace_valid_filter(hisi_ptt, event->attr.config);
 	if (ret < 0)
 		return ret;
-- 
2.34.1