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From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Cc: alexander.shishkin@linux.intel.com, leo.yan@linaro.org,
	suzuki.poulose@arm.com, coresight@lists.linaro.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 3/4] coresight: etm3x: Deal with CLAIM tag before and after accessing HW
Date: Wed,  7 Nov 2018 16:08:51 -0700	[thread overview]
Message-ID: <1541632132-1252-4-git-send-email-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <1541632132-1252-1-git-send-email-mathieu.poirier@linaro.org>

This patch moves access to the CLAIM tag so that no modification to the HW
happens before and after the CLAIM operation has been carried.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 drivers/hwtracing/coresight/coresight-etm3x.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index fd5c4cca7db5..4f638d81a66a 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -363,15 +363,16 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
 
 	CS_UNLOCK(drvdata->base);
 
+	rc = coresight_claim_device_unlocked(drvdata->base);
+	if (rc)
+		goto done;
+
 	/* Turn engine on */
 	etm_clr_pwrdwn(drvdata);
 	/* Apply power to trace registers */
 	etm_set_pwrup(drvdata);
 	/* Make sure all registers are accessible */
 	etm_os_unlock(drvdata);
-	rc = coresight_claim_device_unlocked(drvdata->base);
-	if (rc)
-		goto done;
 
 	etm_set_prog(drvdata);
 
@@ -422,12 +423,11 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
 	etm_clr_prog(drvdata);
 
 done:
-	if (rc)
-		etm_set_pwrdwn(drvdata);
 	CS_LOCK(drvdata->base);
 
-	dev_dbg(drvdata->dev, "cpu: %d enable smp call done: %d\n",
-		drvdata->cpu, rc);
+	if (!rc)
+		dev_dbg(drvdata->dev, "cpu: %d enable smp call done: %d\n",
+			drvdata->cpu, rc);
 	return rc;
 }
 
@@ -577,9 +577,9 @@ static void etm_disable_hw(void *info)
 	for (i = 0; i < drvdata->nr_cntr; i++)
 		config->cntr_val[i] = etm_readl(drvdata, ETMCNTVRn(i));
 
+	etm_set_pwrdwn(drvdata);
 	coresight_disclaim_device_unlocked(drvdata->base);
 
-	etm_set_pwrdwn(drvdata);
 	CS_LOCK(drvdata->base);
 
 	dev_dbg(drvdata->dev, "cpu: %d disable smp call done\n", drvdata->cpu);
-- 
2.7.4


  parent reply	other threads:[~2018-11-07 23:09 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-07 23:08 [PATCH v2 0/4] coresight: Fix miscellaneous problems with CLAIM tags Mathieu Poirier
2018-11-07 23:08 ` [PATCH v2 1/4] coresight: etb10: Add support for CLAIM tag Mathieu Poirier
2018-11-07 23:08 ` [PATCH v2 2/4] coresight: etf: Release CLAIM tag after disabling the HW Mathieu Poirier
2018-11-07 23:08 ` Mathieu Poirier [this message]
2018-11-08 17:13   ` [PATCH v2 3/4] coresight: etm3x: Deal with CLAIM tag before and after accessing HW Suzuki K Poulose
2018-11-09 17:59     ` Mathieu Poirier
2018-11-09 18:06       ` Suzuki K Poulose
2018-11-07 23:08 ` [PATCH v2 4/4] coresight: etm3x: Release CLAIM tag when operated from perf Mathieu Poirier
2018-11-08 17:28   ` Suzuki K Poulose

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