[PATCH 0/3] dev_pm_qos improvements

[PATCH 0/3] dev_pm_qos improvements

[Andy Lutomirski]

Hi Rafael-

Here are three minor dev_pm_qos improvements that make my upcoming
nvme power management code work much better.  Any chance you could
take them for 4.10?

Thanks,
Andy

Andy Lutomirski (3):
  dev_pm_qos: Improve sysfs pm_qos_latency_tolerance validation
  dev_pm_qos: Fix writing 'auto' to pm_qos_latency_tolerance_us
  dev_pm_qos: Export dev_pm_qos_update_user_latency_tolerance

 drivers/base/power/qos.c   | 6 +++++-
 drivers/base/power/sysfs.c | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

-- 
2.9.3

[PATCH 1/3] dev_pm_qos: Improve sysfs pm_qos_latency_tolerance validation

[Andy Lutomirski]

Negative values are special.  Don't let users write them directly.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 drivers/base/power/sysfs.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index a7b46798c81d..33b4b902741a 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -263,7 +263,11 @@ static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
 	s32 value;
 	int ret;
 
-	if (kstrtos32(buf, 0, &value)) {
+	if (kstrtos32(buf, 0, &value) == 0) {
+		/* Users can't write negative values directly */
+		if (value < 0)
+			return -EINVAL;
+	} else {
 		if (!strcmp(buf, "auto") || !strcmp(buf, "auto\n"))
 			value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
 		else if (!strcmp(buf, "any") || !strcmp(buf, "any\n"))
-- 
2.9.3

Re: [PATCH 1/3] dev_pm_qos: Improve sysfs pm_qos_latency_tolerance validation

[Pavel Machek]

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On Tue 2016-11-29 17:11:50, Andy Lutomirski wrote:
> Negative values are special.  Don't let users write them directly.
> 
> Signed-off-by: Andy Lutomirski <luto@kernel.org>

Acked-by: Pavel Machek <pavel@ucw.cz>

> --- a/drivers/base/power/sysfs.c
> +++ b/drivers/base/power/sysfs.c
> @@ -263,7 +263,11 @@ static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
>  	s32 value;
>  	int ret;
>  
> -	if (kstrtos32(buf, 0, &value)) {
> +	if (kstrtos32(buf, 0, &value) == 0) {
> +		/* Users can't write negative values directly */
> +		if (value < 0)
> +			return -EINVAL;
> +	} else {
>  		if (!strcmp(buf, "auto") || !strcmp(buf, "auto\n"))
>  			value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
>  		else if (!strcmp(buf, "any") || !strcmp(buf, "any\n"))

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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[PATCH 2/3] dev_pm_qos: Fix writing 'auto' to pm_qos_latency_tolerance_us

[Andy Lutomirski]

If it was already 'auto', then writing 'auto' again would
incorrectly fail.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 drivers/base/power/qos.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 7f3646e459cb..6a1f2c7e01ea 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -856,7 +856,10 @@ int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
 		struct dev_pm_qos_request *req;
 
 		if (val < 0) {
-			ret = -EINVAL;
+			if (val == PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT)
+				ret = 0;
+			else
+				ret = -EINVAL;
 			goto out;
 		}
 		req = kzalloc(sizeof(*req), GFP_KERNEL);
-- 
2.9.3

[PATCH 3/3] dev_pm_qos: Export dev_pm_qos_update_user_latency_tolerance

[Andy Lutomirski]

nvme wants a module parameter that overrides the default latency
tolerance.  This makes it easy for nvme to reflect that default in
sysfs.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 drivers/base/power/qos.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 6a1f2c7e01ea..58fcc758334e 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -886,6 +886,7 @@ int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(dev_pm_qos_update_user_latency_tolerance);
 
 /**
  * dev_pm_qos_expose_latency_tolerance - Expose latency tolerance to userspace
-- 
2.9.3

Re: [PATCH 0/3] dev_pm_qos improvements

[Rafael J. Wysocki]

On Tuesday, November 29, 2016 05:11:49 PM Andy Lutomirski wrote:
> Hi Rafael-

Hi,

> Here are three minor dev_pm_qos improvements that make my upcoming
> nvme power management code work much better.  Any chance you could
> take them for 4.10?

Yup, all [1-3/3] applied.

Thanks,
Rafael