spurious bL cpufreq driver messages

Viresh Kumar viresh.kumar at linaro.org
Mon May 20 00:36:49 EDT 2013


On 19 May 2013 01:21, Rob Herring <robherring2 at gmail.com> wrote:
> No, it still registers the bL driver. The problem is not that DT data
> is missing, but it is present on a single cluster system.

I misread your mail.. I got the problem now.. Below should fix your
issue (It is rebased on the patch I pointed to you earlier):

Attached too for testing as gmail copy-paste will break it.

@Rafael: Once Rob gives his Tested-by, please queue it for 3.10-rcs

------------x-----------------x-----------------

From: Viresh Kumar <viresh.kumar at linaro.org>
Date: Mon, 20 May 2013 09:57:17 +0530
Subject: [PATCH] cpufreq: arm_big_little_dt: Instantiate as platform_driver

As multiplatform build is being adopted by more and more ARM platforms, initcall
function should be used very carefully. For example, when both arm_big_little_dt
and cpufreq-cpu0 drivers are compiled in, arm_big_little_dt driver may try to
register even if we had platform device for cpufreq-cpu0 registered.

To eliminate this undesired the effect, the patch changes arm_big_little_dt
driver to have it instantiated as a platform_driver. Then it will only run on
platforms that create the platform_device "arm-bL-cpufreq-dt".

Reported-by: Rob Herring <robherring2 at gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar at linaro.org>
---
 drivers/cpufreq/arm_big_little_dt.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/cpufreq/arm_big_little_dt.c
b/drivers/cpufreq/arm_big_little_dt.c
index 27e2f45..fd9e3ea 100644
--- a/drivers/cpufreq/arm_big_little_dt.c
+++ b/drivers/cpufreq/arm_big_little_dt.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/opp.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include "arm_big_little.h"
@@ -95,7 +96,7 @@ static struct cpufreq_arm_bL_ops dt_bL_ops = {
 	.init_opp_table = dt_init_opp_table,
 };

-static int generic_bL_init(void)
+static int generic_bL_probe(struct platform_device *pdev)
 {
 	struct device_node *np;

@@ -106,13 +107,22 @@ static int generic_bL_init(void)
 	of_node_put(np);
 	return bL_cpufreq_register(&dt_bL_ops);
 }
-module_init(generic_bL_init);

-static void generic_bL_exit(void)
+static int generic_bL_remove(struct platform_device *pdev)
 {
-	return bL_cpufreq_unregister(&dt_bL_ops);
+	bL_cpufreq_unregister(&dt_bL_ops);
+	return 0;
 }
-module_exit(generic_bL_exit);
+
+static struct platform_driver generic_bL_platdrv = {
+	.driver = {
+		.name	= "arm-bL-cpufreq-dt",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= generic_bL_probe,
+	.remove		= generic_bL_remove,
+};
+module_platform_driver(generic_bL_platdrv);

 MODULE_AUTHOR("Viresh Kumar <viresh.kumar at linaro.org>");
 MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver via DT");
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