On 10 November 2014 03:34, Paul Bolle [off-list ref] wrote:

On Mon, 2014-11-03 at 11:07 -0700, mathieu.poirier at linaro.org wrote:

quoted

From: Pratik Patel <redacted>

This driver manages CoreSight ETM (Embedded Trace Macrocell) that
supports processor tracing. Currently supported version are ARM
ETMv3.x and PTM1.x.

Signed-off-by: Pratik Patel <redacted>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

coresight-etm3x: adding missing error checking

This landed in today's linx-next (ie, next-20141110) as commit
a939fc5a71ad ("coresight-etm: add CoreSight ETM/PTM driver").

quoted

 arch/arm/Kconfig.debug                 |    9 +
 arch/arm/include/asm/hardware/cp14.h   |  542 +++++++++
 drivers/coresight/Makefile             |    1 +
 drivers/coresight/coresight-etm-cp14.c |  591 ++++++++++
 drivers/coresight/coresight-etm.h      |  251 +++++
 drivers/coresight/coresight-etm3x.c    | 1928 ++++++++++++++++++++++++++++++++
 6 files changed, 3322 insertions(+)
 create mode 100644 arch/arm/include/asm/hardware/cp14.h
 create mode 100644 drivers/coresight/coresight-etm-cp14.c
 create mode 100644 drivers/coresight/coresight-etm.h
 create mode 100644 drivers/coresight/coresight-etm3x.c

[...]

diff --git a/drivers/coresight/coresight-etm3x.c b/drivers/coresight/coresight-etm3x.c
new file mode 100644
index 0000000..d9e3ed6
--- /dev/null
+++ b/drivers/coresight/coresight-etm3x.c

@@ -0,0 +1,1928 @@
+/* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/smp.h>
+#include <linux/sysfs.h>
+#include <linux/stat.h>
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/coresight.h>
+#include <linux/amba/bus.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <asm/sections.h>
+
+#include "coresight-etm.h"
+
+#ifdef CONFIG_CORESIGHT_SOURCE_ETM_DEFAULT_ENABLE

There's no Kconfig symbol CORESIGHT_SOURCE_ETM_DEFAULT_ENABLE. Neither
is there a preprocessor definition of this macro. So why was this
added?

Correct - the feature (as we really want it) is currently being worked
on but not yet part of the code base.  The default option probably
should have been removed but it doesn't do much else when mandating
one to add a boot option on the kernel cmd line.

Thanks for the review,
Mathieu

quoted

+static int boot_enable = 1;
+#else
+static int boot_enable;
+#endif
+module_param_named(
+     boot_enable, boot_enable, int, S_IRUGO
+);

Paul Bolle