From mboxrd@z Thu Jan 1 00:00:00 1970 From: sudeep.holla@arm.com (Sudeep Holla) Date: Thu, 18 Aug 2016 09:47:58 +0100 Subject: how to enable suspend to ram for arm-64 bits In-Reply-To: References: <06a4f0d7-9022-578d-99e0-ddcde31ed895@arm.com> Message-ID: <82ddd0e1-9ecc-5e54-e8ee-86f947fc0ecd@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Yoma, On 18/08/16 03:07, yoma sophian wrote: > hi Sudeep > >> Correct. What's the cpu enable method on your platform ? Is it PSCI ? > No, the enable method is "spin-table" > Generally spin-table is used for the initial bring up. If one is interested in full power management support on a platform, PSCI is the recommended standard on ARM64. >> If yes, does you PSCI implementation support SYSTEM_SUSPEND ? If >> yes, it should work. Check your PSCI implementation otherwise. > > if so, there are 2 things make me curious: a. I trace > arch/arm64/kernel/psci.c even arch/arm64/*, but I sill cannot find > where it create global suspend method table with suspend_set_ops. # > grep -rnw 'suspend_set_ops' ../linux-4.1/arch/arm64/ # drivers/firmware/psci.c > except arch/xxx folder, there are > ../linux-4.1/drivers/macintosh/via-pmu.c:2276: > suspend_set_ops(&pmu_pm_ops); ../linux-4.1/drivers/acpi/sleep.c:666: > suspend_set_ops(old_suspend_ordering ? Does that mean aarch64 > register suspend_set_ops by apci flow when adopt PSCI > implementation? > Not yet, but may choose that from ACPI boot. > b. in arm64, if some platform has its own suspend flow, couldn't it > adopts arm/match-xxx to register its own global suspend method? > No, PSCI is highly recommended. -- Regards, Sudeep