[v4,02/24] PM / devfreq: tegra30: Keep interrupt disabled while governor is stopped
diff mbox series

Message ID 20190707223303.6755-3-digetx@gmail.com
State New
Headers show
Series
  • More improvements for Tegra30 devfreq driver
Related show

Commit Message

Dmitry Osipenko July 7, 2019, 10:32 p.m. UTC
There is no real need to keep interrupt always-enabled, will be nicer
to keep it disabled while governor is inactive.

Suggested-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra30-devfreq.c | 43 ++++++++++++++++---------------
 1 file changed, 22 insertions(+), 21 deletions(-)

Comments

Chanwoo Choi July 16, 2019, 11:47 a.m. UTC | #1
On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote:
> There is no real need to keep interrupt always-enabled, will be nicer
> to keep it disabled while governor is inactive.
> 
> Suggested-by: Thierry Reding <thierry.reding@gmail.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/devfreq/tegra30-devfreq.c | 43 ++++++++++++++++---------------
>  1 file changed, 22 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index a27300f40b0b..5e2b133babdd 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -11,6 +11,7 @@
>  #include <linux/devfreq.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
> +#include <linux/irq.h>
>  #include <linux/module.h>
>  #include <linux/mod_devicetable.h>
>  #include <linux/platform_device.h>
> @@ -416,8 +417,6 @@ static void tegra_actmon_start(struct tegra_devfreq *tegra)
>  {
>  	unsigned int i;
>  
> -	disable_irq(tegra->irq);
> -
>  	actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
>  		      ACTMON_GLB_PERIOD_CTRL);
>  
> @@ -442,8 +441,6 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
>  	}
>  
>  	actmon_write_barrier(tegra);
> -
> -	enable_irq(tegra->irq);
>  }
>  
>  static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
> @@ -552,6 +549,12 @@ static int tegra_governor_event_handler(struct devfreq *devfreq,
>  {
>  	struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent);
>  
> +	/*
> +	 * Couple device with the governor early as it is needed at
> +	 * the moment of governor's start (used by ISR).
> +	 */
> +	tegra->devfreq = devfreq;

I'm not sure it is necessary. Almost devfreq device get
the devfreq instance on probe timing through devfreq_add_device directly.


> +
>  	switch (event) {
>  	case DEVFREQ_GOV_START:
>  		devfreq_monitor_start(devfreq);
> @@ -586,10 +589,11 @@ static struct devfreq_governor tegra_devfreq_governor = {
>  
>  static int tegra_devfreq_probe(struct platform_device *pdev)
>  {
> -	struct tegra_devfreq *tegra;
>  	struct tegra_devfreq_device *dev;
> -	unsigned int i;
> +	struct tegra_devfreq *tegra;
> +	struct devfreq *devfreq;
>  	unsigned long rate;
> +	unsigned int i;
>  	int err;
>  
>  	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
> @@ -625,6 +629,16 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  	}
>  	tegra->irq = err;
>  
> +	irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN);
> +
> +	err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
> +					actmon_thread_isr, IRQF_ONESHOT,
> +					"tegra-devfreq", tegra);
> +	if (err) {
> +		dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
> +		return err;
> +	}
> +
>  	reset_control_assert(tegra->reset);
>  
>  	err = clk_prepare_enable(tegra->clock);
> @@ -672,28 +686,15 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>  	}
>  
>  	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
> -	tegra->devfreq = devfreq_add_device(&pdev->dev,
> -					    &tegra_devfreq_profile,
> -					    "tegra_actmon",
> -					    NULL);
> +	devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
> +				     "tegra_actmon", NULL);
>  	if (IS_ERR(tegra->devfreq)) {

Have to check 'devfreq' instead of 'tegra->devfreq'.
Did you test it? It might be failed because 'tegra->devfreq is NULL.

>  		err = PTR_ERR(tegra->devfreq);

ditto.

>  		goto remove_governor;
>  	}
>  
> -	err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
> -					actmon_thread_isr, IRQF_ONESHOT,
> -					"tegra-devfreq", tegra);
> -	if (err) {
> -		dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
> -		goto remove_devfreq;
> -	}
> -
>  	return 0;
>  
> -remove_devfreq:
> -	devfreq_remove_device(tegra->devfreq);
> -
>  remove_governor:
>  	devfreq_remove_governor(&tegra_devfreq_governor);
>  
>
Dmitry Osipenko July 16, 2019, 1:03 p.m. UTC | #2
16.07.2019 14:47, Chanwoo Choi пишет:
> On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote:
>> There is no real need to keep interrupt always-enabled, will be nicer
>> to keep it disabled while governor is inactive.
>>
>> Suggested-by: Thierry Reding <thierry.reding@gmail.com>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  drivers/devfreq/tegra30-devfreq.c | 43 ++++++++++++++++---------------
>>  1 file changed, 22 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
>> index a27300f40b0b..5e2b133babdd 100644
>> --- a/drivers/devfreq/tegra30-devfreq.c
>> +++ b/drivers/devfreq/tegra30-devfreq.c
>> @@ -11,6 +11,7 @@
>>  #include <linux/devfreq.h>
>>  #include <linux/interrupt.h>
>>  #include <linux/io.h>
>> +#include <linux/irq.h>
>>  #include <linux/module.h>
>>  #include <linux/mod_devicetable.h>
>>  #include <linux/platform_device.h>
>> @@ -416,8 +417,6 @@ static void tegra_actmon_start(struct tegra_devfreq *tegra)
>>  {
>>  	unsigned int i;
>>  
>> -	disable_irq(tegra->irq);
>> -
>>  	actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
>>  		      ACTMON_GLB_PERIOD_CTRL);
>>  
>> @@ -442,8 +441,6 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
>>  	}
>>  
>>  	actmon_write_barrier(tegra);
>> -
>> -	enable_irq(tegra->irq);
>>  }
>>  
>>  static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
>> @@ -552,6 +549,12 @@ static int tegra_governor_event_handler(struct devfreq *devfreq,
>>  {
>>  	struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent);
>>  
>> +	/*
>> +	 * Couple device with the governor early as it is needed at
>> +	 * the moment of governor's start (used by ISR).
>> +	 */
>> +	tegra->devfreq = devfreq;
> 
> I'm not sure it is necessary. Almost devfreq device get
> the devfreq instance on probe timing through devfreq_add_device directly.

This is necessary because this assignment is for the "governor" and not
the "device". Governor is started during of devfreq_add_device(), hence
there is no better way to assign device to the driver's governor.

>> +
>>  	switch (event) {
>>  	case DEVFREQ_GOV_START:
>>  		devfreq_monitor_start(devfreq);
>> @@ -586,10 +589,11 @@ static struct devfreq_governor tegra_devfreq_governor = {
>>  
>>  static int tegra_devfreq_probe(struct platform_device *pdev)
>>  {
>> -	struct tegra_devfreq *tegra;
>>  	struct tegra_devfreq_device *dev;
>> -	unsigned int i;
>> +	struct tegra_devfreq *tegra;
>> +	struct devfreq *devfreq;
>>  	unsigned long rate;
>> +	unsigned int i;
>>  	int err;
>>  
>>  	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
>> @@ -625,6 +629,16 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>  	}
>>  	tegra->irq = err;
>>  
>> +	irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN);
>> +
>> +	err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
>> +					actmon_thread_isr, IRQF_ONESHOT,
>> +					"tegra-devfreq", tegra);
>> +	if (err) {
>> +		dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
>> +		return err;
>> +	}
>> +
>>  	reset_control_assert(tegra->reset);
>>  
>>  	err = clk_prepare_enable(tegra->clock);
>> @@ -672,28 +686,15 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>  	}
>>  
>>  	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
>> -	tegra->devfreq = devfreq_add_device(&pdev->dev,
>> -					    &tegra_devfreq_profile,
>> -					    "tegra_actmon",
>> -					    NULL);
>> +	devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
>> +				     "tegra_actmon", NULL);
>>  	if (IS_ERR(tegra->devfreq)) {
> 
> Have to check 'devfreq' instead of 'tegra->devfreq'.
> Did you test it? It might be failed because 'tegra->devfreq is NULL.

That's a good catch! Thank you very much.

>>  		err = PTR_ERR(tegra->devfreq);
> 
> ditto.

Ok
Chanwoo Choi July 17, 2019, 6:37 a.m. UTC | #3
On 19. 7. 16. 오후 10:03, Dmitry Osipenko wrote:
> 16.07.2019 14:47, Chanwoo Choi пишет:
>> On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote:
>>> There is no real need to keep interrupt always-enabled, will be nicer
>>> to keep it disabled while governor is inactive.
>>>
>>> Suggested-by: Thierry Reding <thierry.reding@gmail.com>
>>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>>> ---
>>>  drivers/devfreq/tegra30-devfreq.c | 43 ++++++++++++++++---------------
>>>  1 file changed, 22 insertions(+), 21 deletions(-)
>>>
>>> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
>>> index a27300f40b0b..5e2b133babdd 100644
>>> --- a/drivers/devfreq/tegra30-devfreq.c
>>> +++ b/drivers/devfreq/tegra30-devfreq.c
>>> @@ -11,6 +11,7 @@
>>>  #include <linux/devfreq.h>
>>>  #include <linux/interrupt.h>
>>>  #include <linux/io.h>
>>> +#include <linux/irq.h>
>>>  #include <linux/module.h>
>>>  #include <linux/mod_devicetable.h>
>>>  #include <linux/platform_device.h>
>>> @@ -416,8 +417,6 @@ static void tegra_actmon_start(struct tegra_devfreq *tegra)
>>>  {
>>>  	unsigned int i;
>>>  
>>> -	disable_irq(tegra->irq);
>>> -
>>>  	actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
>>>  		      ACTMON_GLB_PERIOD_CTRL);
>>>  
>>> @@ -442,8 +441,6 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
>>>  	}
>>>  
>>>  	actmon_write_barrier(tegra);
>>> -
>>> -	enable_irq(tegra->irq);
>>>  }
>>>  
>>>  static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
>>> @@ -552,6 +549,12 @@ static int tegra_governor_event_handler(struct devfreq *devfreq,
>>>  {
>>>  	struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent);
>>>  
>>> +	/*
>>> +	 * Couple device with the governor early as it is needed at
>>> +	 * the moment of governor's start (used by ISR).
>>> +	 */
>>> +	tegra->devfreq = devfreq;
>>
>> I'm not sure it is necessary. Almost devfreq device get
>> the devfreq instance on probe timing through devfreq_add_device directly.
> 
> This is necessary because this assignment is for the "governor" and not
> the "device". Governor is started during of devfreq_add_device(), hence
> there is no better way to assign device to the driver's governor.

OK. I understand.

But, I have a question. Is it working before this patch?
How can you test it on that tegra->devfreq is NULL?

> 
>>> +
>>>  	switch (event) {
>>>  	case DEVFREQ_GOV_START:
>>>  		devfreq_monitor_start(devfreq);
>>> @@ -586,10 +589,11 @@ static struct devfreq_governor tegra_devfreq_governor = {
>>>  
>>>  static int tegra_devfreq_probe(struct platform_device *pdev)
>>>  {
>>> -	struct tegra_devfreq *tegra;
>>>  	struct tegra_devfreq_device *dev;
>>> -	unsigned int i;
>>> +	struct tegra_devfreq *tegra;
>>> +	struct devfreq *devfreq;
>>>  	unsigned long rate;
>>> +	unsigned int i;
>>>  	int err;
>>>  
>>>  	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
>>> @@ -625,6 +629,16 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>>  	}
>>>  	tegra->irq = err;
>>>  
>>> +	irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN);
>>> +
>>> +	err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
>>> +					actmon_thread_isr, IRQF_ONESHOT,
>>> +					"tegra-devfreq", tegra);
>>> +	if (err) {
>>> +		dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
>>> +		return err;
>>> +	}
>>> +
>>>  	reset_control_assert(tegra->reset);
>>>  
>>>  	err = clk_prepare_enable(tegra->clock);
>>> @@ -672,28 +686,15 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>>  	}
>>>  
>>>  	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
>>> -	tegra->devfreq = devfreq_add_device(&pdev->dev,
>>> -					    &tegra_devfreq_profile,
>>> -					    "tegra_actmon",
>>> -					    NULL);
>>> +	devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
>>> +				     "tegra_actmon", NULL);
>>>  	if (IS_ERR(tegra->devfreq)) {
>>
>> Have to check 'devfreq' instead of 'tegra->devfreq'.
>> Did you test it? It might be failed because 'tegra->devfreq is NULL.
> 
> That's a good catch! Thank you very much.
> 
>>>  		err = PTR_ERR(tegra->devfreq);
>>
>> ditto.
> 
> Ok
> 
>
Dmitry Osipenko July 17, 2019, 4:44 p.m. UTC | #4
17.07.2019 9:37, Chanwoo Choi пишет:
> On 19. 7. 16. 오후 10:03, Dmitry Osipenko wrote:
>> 16.07.2019 14:47, Chanwoo Choi пишет:
>>> On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote:
>>>> There is no real need to keep interrupt always-enabled, will be nicer
>>>> to keep it disabled while governor is inactive.
>>>>
>>>> Suggested-by: Thierry Reding <thierry.reding@gmail.com>
>>>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>>>> ---
>>>>  drivers/devfreq/tegra30-devfreq.c | 43 ++++++++++++++++---------------
>>>>  1 file changed, 22 insertions(+), 21 deletions(-)
>>>>
>>>> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
>>>> index a27300f40b0b..5e2b133babdd 100644
>>>> --- a/drivers/devfreq/tegra30-devfreq.c
>>>> +++ b/drivers/devfreq/tegra30-devfreq.c
>>>> @@ -11,6 +11,7 @@
>>>>  #include <linux/devfreq.h>
>>>>  #include <linux/interrupt.h>
>>>>  #include <linux/io.h>
>>>> +#include <linux/irq.h>
>>>>  #include <linux/module.h>
>>>>  #include <linux/mod_devicetable.h>
>>>>  #include <linux/platform_device.h>
>>>> @@ -416,8 +417,6 @@ static void tegra_actmon_start(struct tegra_devfreq *tegra)
>>>>  {
>>>>  	unsigned int i;
>>>>  
>>>> -	disable_irq(tegra->irq);
>>>> -
>>>>  	actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
>>>>  		      ACTMON_GLB_PERIOD_CTRL);
>>>>  
>>>> @@ -442,8 +441,6 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
>>>>  	}
>>>>  
>>>>  	actmon_write_barrier(tegra);
>>>> -
>>>> -	enable_irq(tegra->irq);
>>>>  }
>>>>  
>>>>  static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
>>>> @@ -552,6 +549,12 @@ static int tegra_governor_event_handler(struct devfreq *devfreq,
>>>>  {
>>>>  	struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent);
>>>>  
>>>> +	/*
>>>> +	 * Couple device with the governor early as it is needed at
>>>> +	 * the moment of governor's start (used by ISR).
>>>> +	 */
>>>> +	tegra->devfreq = devfreq;
>>>
>>> I'm not sure it is necessary. Almost devfreq device get
>>> the devfreq instance on probe timing through devfreq_add_device directly.
>>
>> This is necessary because this assignment is for the "governor" and not
>> the "device". Governor is started during of devfreq_add_device(), hence
>> there is no better way to assign device to the driver's governor.
> 
> OK. I understand.
> 
> But, I have a question. Is it working before this patch?
> How can you test it on that tegra->devfreq is NULL?

It was working before this patch because previously interrupt was
requested *after* devfreq_add_device(), now the IRQ requesting happens
*before* devfreq_add_device() and enabling *during of*. If interrupt
fires before the assignment happened, then ISR gets a NULL deference and
this is easily reproducible.

Please note that 'tegra->devfreq' is used only by the ISR and onward, in
the further patches of this series the usage is extended by the cpufreq
notifier.

>>
>>>> +
>>>>  	switch (event) {
>>>>  	case DEVFREQ_GOV_START:
>>>>  		devfreq_monitor_start(devfreq);
>>>> @@ -586,10 +589,11 @@ static struct devfreq_governor tegra_devfreq_governor = {
>>>>  
>>>>  static int tegra_devfreq_probe(struct platform_device *pdev)
>>>>  {
>>>> -	struct tegra_devfreq *tegra;
>>>>  	struct tegra_devfreq_device *dev;
>>>> -	unsigned int i;
>>>> +	struct tegra_devfreq *tegra;
>>>> +	struct devfreq *devfreq;
>>>>  	unsigned long rate;
>>>> +	unsigned int i;
>>>>  	int err;
>>>>  
>>>>  	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
>>>> @@ -625,6 +629,16 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>>>  	}
>>>>  	tegra->irq = err;
>>>>  
>>>> +	irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN);
>>>> +
>>>> +	err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
>>>> +					actmon_thread_isr, IRQF_ONESHOT,
>>>> +					"tegra-devfreq", tegra);
>>>> +	if (err) {
>>>> +		dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
>>>> +		return err;
>>>> +	}
>>>> +
>>>>  	reset_control_assert(tegra->reset);
>>>>  
>>>>  	err = clk_prepare_enable(tegra->clock);
>>>> @@ -672,28 +686,15 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
>>>>  	}
>>>>  
>>>>  	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
>>>> -	tegra->devfreq = devfreq_add_device(&pdev->dev,
>>>> -					    &tegra_devfreq_profile,
>>>> -					    "tegra_actmon",
>>>> -					    NULL);
>>>> +	devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
>>>> +				     "tegra_actmon", NULL);
>>>>  	if (IS_ERR(tegra->devfreq)) {
>>>
>>> Have to check 'devfreq' instead of 'tegra->devfreq'.
>>> Did you test it? It might be failed because 'tegra->devfreq is NULL.
>>
>> That's a good catch! Thank you very much.
>>
>>>>  		err = PTR_ERR(tegra->devfreq);
>>>
>>> ditto.
>>
>> Ok

Patch
diff mbox series

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index a27300f40b0b..5e2b133babdd 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -11,6 +11,7 @@ 
 #include <linux/devfreq.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>
@@ -416,8 +417,6 @@  static void tegra_actmon_start(struct tegra_devfreq *tegra)
 {
 	unsigned int i;
 
-	disable_irq(tegra->irq);
-
 	actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
 		      ACTMON_GLB_PERIOD_CTRL);
 
@@ -442,8 +441,6 @@  static void tegra_actmon_stop(struct tegra_devfreq *tegra)
 	}
 
 	actmon_write_barrier(tegra);
-
-	enable_irq(tegra->irq);
 }
 
 static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
@@ -552,6 +549,12 @@  static int tegra_governor_event_handler(struct devfreq *devfreq,
 {
 	struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent);
 
+	/*
+	 * Couple device with the governor early as it is needed at
+	 * the moment of governor's start (used by ISR).
+	 */
+	tegra->devfreq = devfreq;
+
 	switch (event) {
 	case DEVFREQ_GOV_START:
 		devfreq_monitor_start(devfreq);
@@ -586,10 +589,11 @@  static struct devfreq_governor tegra_devfreq_governor = {
 
 static int tegra_devfreq_probe(struct platform_device *pdev)
 {
-	struct tegra_devfreq *tegra;
 	struct tegra_devfreq_device *dev;
-	unsigned int i;
+	struct tegra_devfreq *tegra;
+	struct devfreq *devfreq;
 	unsigned long rate;
+	unsigned int i;
 	int err;
 
 	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
@@ -625,6 +629,16 @@  static int tegra_devfreq_probe(struct platform_device *pdev)
 	}
 	tegra->irq = err;
 
+	irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN);
+
+	err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
+					actmon_thread_isr, IRQF_ONESHOT,
+					"tegra-devfreq", tegra);
+	if (err) {
+		dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
+		return err;
+	}
+
 	reset_control_assert(tegra->reset);
 
 	err = clk_prepare_enable(tegra->clock);
@@ -672,28 +686,15 @@  static int tegra_devfreq_probe(struct platform_device *pdev)
 	}
 
 	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
-	tegra->devfreq = devfreq_add_device(&pdev->dev,
-					    &tegra_devfreq_profile,
-					    "tegra_actmon",
-					    NULL);
+	devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
+				     "tegra_actmon", NULL);
 	if (IS_ERR(tegra->devfreq)) {
 		err = PTR_ERR(tegra->devfreq);
 		goto remove_governor;
 	}
 
-	err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
-					actmon_thread_isr, IRQF_ONESHOT,
-					"tegra-devfreq", tegra);
-	if (err) {
-		dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
-		goto remove_devfreq;
-	}
-
 	return 0;
 
-remove_devfreq:
-	devfreq_remove_device(tegra->devfreq);
-
 remove_governor:
 	devfreq_remove_governor(&tegra_devfreq_governor);