On 二, 2012-09-18 at 02:11 -0600, R, Durgadoss wrote: > Hi Rui, > > > > -----Original Message----- > > From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- > > owner@xxxxxxxxxxxxxxx] On Behalf Of Zhang Rui > > Sent: Tuesday, September 18, 2012 12:44 PM > > To: R, Durgadoss > > Cc: lenb@xxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; eduardo.valentin@xxxxxx > > Subject: Re: [PATCHv4 11/15] Thermal: Introduce a step_wise thermal > > governor > > > > On 二, 2012-09-18 at 11:05 +0530, Durgadoss R wrote: > > > This patch adds a simple step_wise governor to the > > > generic thermal layer. This algorithm throttles the > > > cooling devices in a linear fashion. If the 'trend' > > > is heating, it throttles by one step. And if the > > > thermal trend is cooling it de-throttles by one step. > > > > > > This actually moves the throttling logic from thermal_sys.c > > > and puts inside step_wise.c, without any change. This is > > > always selected as the default governor. > > > > > > Signed-off-by: Durgadoss R <durgadoss.r@xxxxxxxxx> > > > --- > > > drivers/thermal/Kconfig | 7 ++ > > > drivers/thermal/Makefile | 1 + > > > drivers/thermal/step_wise.c | 194 > > +++++++++++++++++++++++++++++++++++++++++++ > > > 3 files changed, 202 insertions(+) > > > create mode 100644 drivers/thermal/step_wise.c > > > > > > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > > > index 2200912..9f6a3aa 100644 > > > --- a/drivers/thermal/Kconfig > > > +++ b/drivers/thermal/Kconfig > > > @@ -4,6 +4,7 @@ > > > > > > menuconfig THERMAL > > > tristate "Generic Thermal sysfs driver" > > > + select STEP_WISE > > > help > > > Generic Thermal Sysfs driver offers a generic mechanism for > > > thermal management. Usually it's made up of one or more thermal > > > @@ -59,3 +60,9 @@ config FAIR_SHARE > > > depends on THERMAL > > > help > > > Enable this to manage platform thermals using fair-share governor. > > > + > > > +config STEP_WISE > > > + bool "Step_wise thermal governor" > > > + depends on THERMAL > > > + help > > > + Enable this to manage platform thermals using a simple linear > > > > if we always wants CONFIG_STEP_WISE built in, why bother to export this > > config option to users? > > > > IMO, something like > > menuconfig THERMAL > > tristate "Generic Thermal sysfs driver" > > select STEP_WISE > > > > config STEP_WISE > > bool > > depends on THERMAL > > > > is enough, SETP_WISE will always be selected. > > > > further more, we even do not need a config option for this governor, > > just "obj-y += step_wise.o" in Makefile. > > Yes, Thought through this. But I thought it would be good to align this > with the rest of the governors. > we'd better follow cpufreq governor to allow users to select the default governor, or else this configure option is needless because we never want it to be cleared with CONFIG_THERMAL=y. > > > > another question would be, > > as this governor registration function is fs_initcall(), > > what if a platform thermal driver is registered and gets a thermal event > > before this governor being registered? > > Wonder if this can happen with the current code, since the > thermal_sys.c also loads with fs_initcall. > you're right. this is not a problem. thanks, rui -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
