[PATCH v2] hwtracing: hisi_ptt: Move type check to the beginning of hisi_ptt_pmu_event_init()

From: Yang Jihong
Date: Mon Jan 08 2024 - 07:23:27 EST


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@xxxxxxxxxx>
---

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