From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753380AbcADLWb (ORCPT ); Mon, 4 Jan 2016 06:22:31 -0500 Received: from mail-wm0-f47.google.com ([74.125.82.47]:34365 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752758AbcADLW3 (ORCPT ); Mon, 4 Jan 2016 06:22:29 -0500 Subject: Re: [PATCH v2] thermal: re-calculate k_po/k_pu when update sustainable power To: Leo Yan , Eduardo Valentin References: <1451471920-2148-1-git-send-email-leo.yan@linaro.org> <20151231172125.GA11863@localhost.localdomain> <20160101000347.GA2572@leoy-linaro> Cc: Zhang Rui , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, javi.merino@arm.com From: Daniel Thompson Message-ID: <568A55F2.10800@linaro.org> Date: Mon, 4 Jan 2016 11:22:26 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20160101000347.GA2572@leoy-linaro> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 >>> --- >>> 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... > > Thanks, > Leo Yan > >> >>> return count; >>> } >>> static DEVICE_ATTR(sustainable_power, S_IWUSR | S_IRUGO, sustainable_power_show, >>> -- >>> 1.9.1 >>> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >