linux-kernel - [PATCH AUTOSEL for 4.4 094/101] coresight: Fix disabling of CoreSight TPIU

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Message-ID: <20180308050023.8548-94-alexander.levin@microsoft.com>
Date:   Thu, 8 Mar 2018 05:02:14 +0000
From:   Sasha Levin <Alexander.Levin@...rosoft.com>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
CC:     Robert Walker <robert.walker@....com>,
        Mathieu Poirier <mathieu.poirier@...aro.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Sasha Levin <Alexander.Levin@...rosoft.com>
Subject: [PATCH AUTOSEL for 4.4 094/101] coresight: Fix disabling of CoreSight
 TPIU

From: Robert Walker <robert.walker@....com>

[ Upstream commit 11595db8e17faaa05fadc25746c870e31276962f ]

The CoreSight TPIU should be disabled when tracing to other sinks to allow
them to operate at full bandwidth.

This patch fixes tpiu_disable_hw() to correctly disable the TPIU by
configuring the TPIU to stop on flush, initiating a manual flush, waiting
for the flush to complete and then waits for the TPIU to indicate it has
stopped.

Signed-off-by: Robert Walker <robert.walker@....com>
Tested-by: Mike Leach <mike.leach@...aro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
---
 drivers/hwtracing/coresight/coresight-tpiu.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index 7214efd10db5..22e10b7d505d 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -45,8 +45,11 @@
 #define TPIU_ITATBCTR0		0xef8
 
 /** register definition **/
+/* FFSR - 0x300 */
+#define FFSR_FT_STOPPED		BIT(1)
 /* FFCR - 0x304 */
 #define FFCR_FON_MAN		BIT(6)
+#define FFCR_STOP_FI		BIT(12)
 
 /**
  * @base:	memory mapped base address for this component.
@@ -85,10 +88,14 @@ static void tpiu_disable_hw(struct tpiu_drvdata *drvdata)
 {
 	CS_UNLOCK(drvdata->base);
 
-	/* Clear formatter controle reg. */
-	writel_relaxed(0x0, drvdata->base + TPIU_FFCR);
+	/* Clear formatter and stop on flush */
+	writel_relaxed(FFCR_STOP_FI, drvdata->base + TPIU_FFCR);
 	/* Generate manual flush */
-	writel_relaxed(FFCR_FON_MAN, drvdata->base + TPIU_FFCR);
+	writel_relaxed(FFCR_STOP_FI | FFCR_FON_MAN, drvdata->base + TPIU_FFCR);
+	/* Wait for flush to complete */
+	coresight_timeout(drvdata->base, TPIU_FFCR, FFCR_FON_MAN, 0);
+	/* Wait for formatter to stop */
+	coresight_timeout(drvdata->base, TPIU_FFSR, FFSR_FT_STOPPED, 1);
 
 	CS_LOCK(drvdata->base);
 }
-- 
2.14.1