Hi, I'm running a AM335X custom board with Linux 4.10 and now I want to optimize the power consumption. For this I'm following http://processors.wiki.ti.com/index.php/Linux_Core_Power_Management_User%27s_Guide_(v4.1) and read also https://www.kernel.org/doc/Documentation/power/states.txt My initial thought was to use suspend-to-ram, but somehow I didn't manage to configure the kernel correctly to allow me these options: root@evalboard:~# dmesg | grep -i CM3 [ 1.132443] wkup_m3_ipc 44e11324.wkup_m3_ipc: CM3 Firmware Version = 0x192 root@board:~# cat /sys/power/state freeze mem root@board:~# cat /sys/power/mem_sleep [s2idle] Looking at the commits, it seems that this only works from Kernel V4.16/17, or more exactly from Tony's commit d33ae255254ce35dd7ed1f4d3cdfb7abdb1d8dd4 ( At least CONFIG_AMX3_PM=y wasn't in the defconfig until then) Is my understanding correct that suspend to RAM didn't work on V4.10, or did it work using a different kernel config? My Low Power config looks as follows: CONFIG_ARM_OMAP2PLUS_CPUFREQ=y # CONFIG_QORIQ_CPUFREQ is not set CONFIG_DT_IDLE_STATES=y CONFIG_ARM_CPUIDLE=y # CONFIG_ARM_HIGHBANK_CPUIDLE is not set # CONFIG_SUSPEND_SKIP_SYNC is not set CONFIG_PM_ADVANCED_DEBUG=y CONFIG_FIRMWARE_IN_KERNEL=y CONFIG_EXTRA_FIRMWARE="am335x-pm-firmware.elf" CONFIG_EXTRA_FIRMWARE_DIR="firmware" CONFIG_ARM_PSCI_FW=y CONFIG_RTC_DRV_OMAP=m CONFIG_FW_LOADER=y # CONFIG_VIRTIO_BLK is not set # CONFIG_SCSI_VIRTIO is not set # CONFIG_VIRTIO_NET is not set # CONFIG_VIRTIO_CONSOLE is not set # CONFIG_HW_RANDOM_VIRTIO is not set # CONFIG_DRM_VIRTIO_GPU is not set CONFIG_VIRTIO=y # CONFIG_VIRTIO_BALLOON is not set # CONFIG_VIRTIO_INPUT is not set CONFIG_REMOTEPROC=y CONFIG_WKUP_M3_RPROC=y CONFIG_CRYPTO_DEV_VIRTIO=m CONFIG_VIRTUALIZATION=y # CONFIG_VHOST_NET is not set # CONFIG_VHOST_CROSS_ENDIAN_LEGACY is not set # AMx3 Power Config Options (Copied from the TI guide) CONFIG_MAILBOX=y CONFIG_OMAP2PLUS_MBOX=y CONFIG_SOC_TI=y CONFIG_WKUP_M3_IPC=y CONFIG_TI_EMIF_SRAM=y CONFIG_AMX3_PM=y Best regards Isak
