From 0062176317ff0c89a10fc299e2775688ad8ce0b1 Mon Sep 17 00:00:00 2001
From: Robin Murphy <robin.murphy@arm.com>
Date: Mon, 21 May 2018 12:17:09 +0100
Subject: [PATCH 072/105] perf/arm-cci: Remove unnecessary period adjustment
Git-commit: 5c591304e710339a75a9f0f9f3f085aa4109e55d
Patch-mainline: v4.18-rc1
References: fate#325865,fate#325861
Since sampling events are rejected up-front by cci_pmu_event_init(), it
doesn't make much sense to go fiddling with the sampling period later.
This would seem to be just another leftover artefact of the arm_pmu
framwork, and as such can go.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
drivers/perf/arm-cci.c | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c
index 67a74c48c7c2..62b38225bb07 100644
--- a/drivers/perf/arm-cci.c
+++ b/drivers/perf/arm-cci.c
@@ -1304,15 +1304,6 @@ static int __hw_perf_event_init(struct perf_event *event)
*/
hwc->config_base |= (unsigned long)mapping;
- /*
- * Limit the sample_period to half of the counter width. That way, the
- * new counter value is far less likely to overtake the previous one
- * unless you have some serious IRQ latency issues.
- */
- hwc->sample_period = CCI_PMU_CNTR_MASK >> 1;
- hwc->last_period = hwc->sample_period;
- local64_set(&hwc->period_left, hwc->sample_period);
-
if (event->group_leader != event) {
if (validate_group(event) != 0)
return -EINVAL;
--
2.11.0