* [PATCH] coresight: add PM runtime calls to coresight_simple_func()
@ 2016-06-17 17:41 Mathieu Poirier
2016-06-23 16:37 ` Sudeep Holla
0 siblings, 1 reply; 3+ messages in thread
From: Mathieu Poirier @ 2016-06-17 17:41 UTC (permalink / raw)
To: linux-arm-kernel; +Cc: linux-kernel
It is mandatory to enable a coresight block's power domain before
trying to access management registers. Otherwise the transaction
simply stalls, leading to a system hang.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/hwtracing/coresight/coresight-priv.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index ad975c58080d..b047241e7496 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -16,6 +16,7 @@
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/coresight.h>
+#include <linux/pm_runtime.h>
/*
* Coresight management registers (0xf00-0xfcc)
@@ -42,8 +43,10 @@ static ssize_t name##_show(struct device *_dev, \
struct device_attribute *attr, char *buf) \
{ \
type *drvdata = dev_get_drvdata(_dev->parent); \
+ pm_runtime_get_sync(_dev->parent); \
return scnprintf(buf, PAGE_SIZE, "0x%x\n", \
readl_relaxed(drvdata->base + offset)); \
+ pm_runtime_put_sync(_dev->parent); \
} \
static DEVICE_ATTR_RO(name)
--
2.5.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] coresight: add PM runtime calls to coresight_simple_func()
2016-06-17 17:41 [PATCH] coresight: add PM runtime calls to coresight_simple_func() Mathieu Poirier
@ 2016-06-23 16:37 ` Sudeep Holla
2016-06-23 17:10 ` Mathieu Poirier
0 siblings, 1 reply; 3+ messages in thread
From: Sudeep Holla @ 2016-06-23 16:37 UTC (permalink / raw)
To: Mathieu Poirier, linux-arm-kernel; +Cc: Sudeep Holla, linux-kernel
On 17/06/16 18:41, Mathieu Poirier wrote:
> It is mandatory to enable a coresight block's power domain before
> trying to access management registers. Otherwise the transaction
> simply stalls, leading to a system hang.
>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> ---
> drivers/hwtracing/coresight/coresight-priv.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index ad975c58080d..b047241e7496 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -16,6 +16,7 @@
> #include <linux/bitops.h>
> #include <linux/io.h>
> #include <linux/coresight.h>
> +#include <linux/pm_runtime.h>
>
> /*
> * Coresight management registers (0xf00-0xfcc)
> @@ -42,8 +43,10 @@ static ssize_t name##_show(struct device *_dev, \
> struct device_attribute *attr, char *buf) \
> { \
> type *drvdata = dev_get_drvdata(_dev->parent); \
> + pm_runtime_get_sync(_dev->parent); \
> return scnprintf(buf, PAGE_SIZE, "0x%x\n", \
> readl_relaxed(drvdata->base + offset)); \
> + pm_runtime_put_sync(_dev->parent); \
This is wrong, I just noticed when I was playing around this.
Perhaps you meant to do this before returning ? I wonder why compiler
doesn't throw any error.
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] coresight: add PM runtime calls to coresight_simple_func()
2016-06-23 16:37 ` Sudeep Holla
@ 2016-06-23 17:10 ` Mathieu Poirier
0 siblings, 0 replies; 3+ messages in thread
From: Mathieu Poirier @ 2016-06-23 17:10 UTC (permalink / raw)
To: Sudeep Holla; +Cc: linux-arm-kernel, linux-kernel
On 23 June 2016 at 10:37, Sudeep Holla <sudeep.holla@arm.com> wrote:
>
>
> On 17/06/16 18:41, Mathieu Poirier wrote:
>>
>> It is mandatory to enable a coresight block's power domain before
>> trying to access management registers. Otherwise the transaction
>> simply stalls, leading to a system hang.
>>
>> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>> ---
>> drivers/hwtracing/coresight/coresight-priv.h | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-priv.h
>> b/drivers/hwtracing/coresight/coresight-priv.h
>> index ad975c58080d..b047241e7496 100644
>> --- a/drivers/hwtracing/coresight/coresight-priv.h
>> +++ b/drivers/hwtracing/coresight/coresight-priv.h
>> @@ -16,6 +16,7 @@
>> #include <linux/bitops.h>
>> #include <linux/io.h>
>> #include <linux/coresight.h>
>> +#include <linux/pm_runtime.h>
>>
>> /*
>> * Coresight management registers (0xf00-0xfcc)
>> @@ -42,8 +43,10 @@ static ssize_t name##_show(struct device *_dev,
>> \
>> struct device_attribute *attr, char *buf) \
>> { \
>> type *drvdata = dev_get_drvdata(_dev->parent); \
>> + pm_runtime_get_sync(_dev->parent); \
>> return scnprintf(buf, PAGE_SIZE, "0x%x\n", \
>> readl_relaxed(drvdata->base + offset)); \
>> + pm_runtime_put_sync(_dev->parent); \
>
>
> This is wrong, I just noticed when I was playing around this.
> Perhaps you meant to do this before returning ? I wonder why compiler
> doesn't throw any error.
Yes of course - I'll respin.
>
> --
> Regards,
> Sudeep
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-06-23 16:37 ` Sudeep Holla
2016-06-23 17:10 ` Mathieu Poirier
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