From: Javi Merino <javi.merino@arm.com>
To: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>,
Eduardo Valentin <edubezval@gmail.com>,
Zhang Rui <rui.zhang@intel.com>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
Punit Agrawal <Punit.Agrawal@arm.com>
Subject: Re: [PATCH v2] thermal: re-calculate k_po/k_pu when update sustainable power
Date: Tue, 5 Jan 2016 16:33:29 +0000 [thread overview]
Message-ID: <20160105163328.GB3163@e104805> (raw)
In-Reply-To: <568A55F2.10800@linaro.org>
On Mon, Jan 04, 2016 at 11:22:26AM +0000, Daniel Thompson wrote:
> On 01/01/16 00:03, Leo Yan wrote:
> >Hi Eduardo,
> >
> >Thanks for review.
> >
> >On Thu, Dec 31, 2015 at 09:21:26AM -0800, Eduardo Valentin wrote:
> >>On Wed, Dec 30, 2015 at 06:38:40PM +0800, Leo Yan wrote:
> >>>k_po/k_pu are in essence ratio values compared with sustainable power.
> >>>So when update sustainable power, we can recalculate k_po/k_pu simply
> >>>with below formula:
> >>>
> >>> sustainable_power(new)
> >>> k_p(new) = ---------------------- * k_p(old)
> >>> sustainable_power(old)
> >>>
> >>>Signed-off-by: Leo Yan <leo.yan@linaro.org>
> >>>---
> >>> drivers/thermal/thermal_core.c | 6 +++++-
> >>> 1 file changed, 5 insertions(+), 1 deletion(-)
> >>>
> >>>diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> >>>index d9e525c..223f8df 100644
> >>>--- a/drivers/thermal/thermal_core.c
> >>>+++ b/drivers/thermal/thermal_core.c
> >>>@@ -908,7 +908,7 @@ sustainable_power_store(struct device *dev, struct device_attribute *devattr,
> >>> const char *buf, size_t count)
> >>> {
> >>> struct thermal_zone_device *tz = to_thermal_zone(dev);
> >>>- u32 sustainable_power;
> >>>+ u32 sustainable_power, old_val;
> >>>
> >>> if (!tz->tzp)
> >>> return -EIO;
> >>>@@ -916,8 +916,12 @@ sustainable_power_store(struct device *dev, struct device_attribute *devattr,
> >>> if (kstrtou32(buf, 10, &sustainable_power))
> >>> return -EINVAL;
> >>>
> >>>+ old_val = tz->tzp->sustainable_power;
> >>>+
> >>> tz->tzp->sustainable_power = sustainable_power;
> >>>
> >>>+ tz->tzp->k_po = (tz->tzp->k_po * sustainable_power) / old_val;
> >>>+ tz->tzp->k_pu = (tz->tzp->k_pu * sustainable_power) / old_val;
> >>
> >>I believe this has to be done by the governor. These properties are
> >>power_allocator specific. thermal_core should not really care about
> >>them.
> >
> >Okay, I will try to update these properties in power_allocator.c.
> >Javi, do you think this is fine for you?
>
> If sustainable power were to change frequently (perhaps on
> entry/exit of a fan inhibitor mode?) then we would accumulate
> rounding errors here...
Can you elaborate on the use case? What is this fan inhibitor mode?
next prev parent reply other threads:[~2016-01-05 16:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-30 10:38 [PATCH v2] thermal: re-calculate k_po/k_pu when update sustainable power Leo Yan
2015-12-31 17:21 ` Eduardo Valentin
2016-01-01 0:03 ` Leo Yan
2016-01-04 11:22 ` Daniel Thompson
2016-01-04 14:31 ` Leo Yan
2016-01-05 16:33 ` Javi Merino [this message]
2016-01-05 16:50 ` Daniel Thompson
2016-01-05 17:40 ` Punit Agrawal
2016-01-05 18:02 ` Daniel Thompson
2016-01-05 16:31 ` Javi Merino
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