Hi Rui, On 12/5/18 4:08 PM, Zhang Rui wrote: > On 三, 2018-11-07 at 18:09 +0100, Lukasz Luba wrote: >> Hi all, >> >> This patch set adds a new flag and mechanism in thermal trip points >> in >> DT. The old implementation in thermal zone in DT sets the same >> configuration for all internal trip points. It does not work for all >> HW. There are SoCs which support IRQs for some trip points (i.e. >> Exynos 4 has 4 trip points with IRQs). For additional one defined >> inside the thermal zone there is a need of 'polling'. When developer >> adds polling mode settings inside the thermal zone, all the trip >> points will be registered for polling, even those supporting IRQs, >> which does not make sense. > > we have two timers, one for polling, and one for passive cooling. > I think we are talking about passive cooling timer only, right? > And the real problem is that we have multiple passive trip points and > only part of them support irq_mode, and we don't want to start the > passive polling timer for all of the passive trip points. Yes exactly, we don't want to poll all of them by starting 'passive polling timer'. Regards, Lukasz > > thanks, > rui > >> Thus, developers create workarounds, which >> are confusing for some other developers. To workaround, >> people declare some trip points as 'active' (those with IRQ support). >> It allows to bypass polling mode in thermal framework applied for >> all thermal zone's trip points. >> >> Thermal framework defines 4 types of trip points. The 'passive' means >> passive cooling using DVFS, 'active' is designed for fan and other >> devices actively changing the outside conditions. Therefore, a >> workaround >> mentioned earlier is confusing when someone does not know about the >> framework limitations. >> >> This patch set tries to solve the issue by adding one flag inside the >> trip point: 'irq-mode;'. The trip point 'passive' declared in DT >> with >> explicit flag 'irq-mode;' will not register itself as polling mode. >> Thermal framework will skip it during scheduling next read out work. >> The old global-polling-mode-configuration-inside-thermal-zone is >> still >> valid. Patch set does not break existing design for trip points >> which >> do not have 'irq-mode' flag - they will use polling. >> >> As an example please check patch #10 for Exynos4 SoC family, where >> there >> is 4 HW supported trip points and there is a need of 6. The rest 2 >> are >> declared as 'passive' without 'irq-mode;' flag, which means polling >> mode needed for them. >> >> Patch #1 is a small cleanup in thermal framework. >> >> Change log: >> v2 >> - changed description in cover letter >> - change commit messages according to Krzysztof comments >> - rebase on top of current mainline (v4.20-rc1) >> >> Regards, >> Lukasz Luba >> >> Lukasz Luba (11): >> thermal: remove unused function parameter >> thermal: add irq-mode configuration for trip point >> thermal: add new sysfs file for irq-mode >> Doc: thermal: new irq-mode for trip point >> Doc: DT: thermal: new irq-mode for trip point >> arm64: dts: exynos5433: add support for thermal trip irq-mode >> arm64: dts: exynos7: add support for thermal trip irq-mode >> arm: dts: exynos4: add support for thermal trip irq-mode >> arm: dts: exynos5420: add support for thermal trip irq-mode >> arm: dts: exynos5422: add support for thermal trip irq-mode >> arm: dts: exynos5410: add support for thermal trip irq-mode >> >> .../devicetree/bindings/thermal/thermal.txt | 7 ++ >> Documentation/thermal/sysfs-api.txt | 9 ++ >> arch/arm/boot/dts/exynos4-cpu-thermal.dtsi | 10 +- >> arch/arm/boot/dts/exynos5410-odroidxu.dts | 10 +- >> arch/arm/boot/dts/exynos5420-trip-points.dtsi | 10 +- >> arch/arm/boot/dts/exynos5422-odroidxu3-common.dtsi | 40 +++++--- >> arch/arm64/boot/dts/exynos/exynos5433-tmu.dtsi | 105 >> ++++++++++++++------- >> .../arm64/boot/dts/exynos/exynos7-trip-points.dtsi | 8 ++ >> drivers/thermal/of-thermal.c | 17 ++++ >> drivers/thermal/thermal_core.c | 16 ++-- >> drivers/thermal/thermal_sysfs.c | 53 ++++++++++- >> include/linux/thermal.h | 5 + >> 12 files changed, 226 insertions(+), 64 deletions(-) >> > >
