> -----Original Message----- > From: Shawn Guo [mailto:[email protected]] > Sent: 2015年9月18日 9:15 > To: Wang Shenwei-B38339 > Cc: [email protected]; Huang Yongcai-B20788; > [email protected]; [email protected]; Sudeep Holla; > [email protected]; [email protected]; [email protected] > 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. Thanks, Shenwei > Shawn > > [1] http://lists.denx.de/pipermail/u-boot/2013-December/168655.html N�Р骒r��y����b�X�肚�v�^�)藓{.n�+�伐�{��赙zXФ�≤�}��财�z�&j:+v�����赙zZ+��+zf＂�h���~����i���z� �wア�?�ㄨ��&�)撷f��^j谦y�m��@A�a囤� 0鹅h���i
