Re: [PATCH] coresight: add PM runtime calls to coresight_simple_func()
From: Mathieu Poirier
Date: Thu Jun 23 2016 - 13:10:36 EST
On 23 June 2016 at 10:37, Sudeep Holla <sudeep.holla@xxxxxxx> 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@xxxxxxxxxx>
>> ---
>> 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