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From:   Anshuman Khandual <anshuman.khandual@arm.com>
To:     linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org
Cc:     linux-kernel@vger.kernel.org,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Linu Cherian <lcherian@marvell.com>
Subject: [PATCH 09/11] coresight: etm-perf: Truncate the perf record if handle has no space
Date:   Wed, 23 Dec 2020 15:33:41 +0530
Message-Id: <1608717823-18387-10-git-send-email-anshuman.khandual@arm.com>
In-Reply-To: <1608717823-18387-1-git-send-email-anshuman.khandual@arm.com>
References: <1608717823-18387-1-git-send-email-anshuman.khandual@arm.com>
Precedence: bulk

While starting off the etm event, just abort and truncate the perf record
if the perf handle as no space left. This avoids configuring both source
and sink devices in case the data cannot be consumed in perf.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm-perf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index eb9e7e9..e776a07 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -347,6 +347,9 @@ static void etm_event_start(struct perf_event *event, int flags)
 	if (!event_data)
 		goto fail;
 
+	if (!handle->size)
+		goto fail_end_stop;
+
 	/*
 	 * Check if this ETM is allowed to trace, as decided
 	 * at etm_setup_aux(). This could be due to an unreachable
-- 
2.7.4