On Fri, Sep 18, 2015 at 8:12 PM, Shawn Guo <shawn...@kernel.org> wrote: > On Fri, Sep 18, 2015 at 02:38:39PM +0000, Shenwei Wang wrote: >> >> >> > -----Original Message----- >> > From: Shawn Guo [mailto:shawn...@kernel.org] >> > Sent: 2015年9月18日 9:15 >> > To: Wang Shenwei-B38339 >> > Cc: ja...@lakedaemon.net; Huang Yongcai-B20788; >> > linux-kernel@vger.kernel.org; ker...@pengutronix.de; Sudeep Holla; >> > t...@linutronix.de; shawn....@linaro.org; >> > linux-arm-ker...@lists.infradead.org >> > Subject: Re: [PATCH v8 2/2] ARM: imx: support suspend states on imx7D >> > >> > On Tue, Sep 08, 2015 at 03:01:07PM +0000, Shenwei Wang wrote: >> > > > > arch/arm/mach-imx/Kconfig | 1 + >> > > > > arch/arm/mach-imx/Makefile | 2 + >> > > > > arch/arm/mach-imx/common.h | 4 + >> > > > > arch/arm/mach-imx/pm-imx7.c | 917 >> > > > +++++++++++++++++++++++++++++++++++++++ >> > > > > arch/arm/mach-imx/suspend-imx7.S | 529 ++++++++++++++++++++++ >> > > > > 5 files changed, 1453 insertions(+) >> > > > >> > > > 1453 lines addition to kernel only for i.MX7D suspend support. Yes, >> > > > this is the way we support suspend on i.MX6, but that's enough, and >> > > > we have to stop this somewhere. I would ask you to take Sudeep's >> > > > comment and adopt PSCI for i.MX7D power management. >> > > >> > > According to PSCI spec, a supervisory software must be implemented >> > > under either >> > > HVC(EL2) or SMC(EL3) privilege level. I agree that, with this idea, we >> > > could finally move these 1453 lines of codes from kernel into a >> > > platform specific firmware. The problem is we don't have the firmware >> > > so far, and we haven't even had a plan to enable the hypervisor or >> > > secure software on this platform. Because low power consumption is the >> > > key feature of this i.MX7D platform, please continue to consider the >> > > current >> > implementation and get this feature supported first. >> > >> > Can't U-Boot be considered as a firmware to implement PSCI? I have seen an >> > initial ARMv7 PSCI core support for U-Boot added by Marc Zyngier. >> >> The current PSCI support in uboot is not complete. It can now support >> cpuidle, shutdown, >> and reset. But to support system suspend, there would be a lot more tasks. >> For example, >> even the current wakeup source management codes will have to move into the >> firmware >> too. It is not a short time task. Please continue to consider this platform >> dependent implementation >> first, meanwhile, we will start to migrate the solution to PSCI. However it >> will take some time. > > I have zero interest to maintain this pile of code in the mainline > kernel. Take it as a motivation to move to PSCI soon, or you maintain > it on your own as a out-of-tree patch for whatever long time you like. >
Does it means that SMP support also need go through PSCI? best regards Frank Li > Shawn > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-ker...@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
