Guidance for Low Power Mode on i.MX8MP Hi NXP Team, I am working on a custom product based on i.MX8M Plus (i.MX8MP) using Yocto Linux and BusyBox userspace. Current hardware configuration: i.MX8MP LA9410 connected through PCIe LTE modem (u-blox LARA-L6) connected through USB MIPI CSI camera connected to i.MX8MP Yocto BSP based Linux BusyBox rootfs Project requirement: We need to implement low power operation with: Low latency wakeup Fast resume back to normal operation PCIe and USB subsystem stability after resume Camera pipeline recovery after wakeup LTE modem reconnect/resume support We are currently evaluating: WAIT mode STOP mode DSM (Deep Sleep Mode) From the Reference Manual and AN13400, DSM gives maximum power saving, but our concern is wakeup latency and peripheral resume stability. Main questions: Which low power mode is recommended for this use case? WAIT STOP DSM For low latency wakeup with PCIe + USB + camera active systems, is suspend-to-idle preferred over deep suspend? Are there any known limitations for: PCIe device resume (LA9310) USB LTE modem resume CSI camera recovery after suspend Which BSP version/kernel is most stable for low power support on i.MX8MP? We are currently considering: LF 6.6.3 BSP Yocto Nanbield Are there recommended SDKs, patches, or reference implementations for: PCIe wakeup USB wakeup Runtime PM DSM entry/exit Low latency suspend/resume Is there any recommended approach for keeping LTE connectivity partially active while reducing overall system power? Reference documents we are studying: AN13400: i.MX 8M Low Power Design By M Core Running i.MX8MP Reference Manual Chapter 5 (GPC / Low Power) Linux PM framework gpcv2 driver Any guidance, reference SDKs, Yocto layers, example DTS configurations, or suspend/resume debug methods would be very helpful. Thank you. FRDM-Training Hands-On Training HW-Open-Source i.MX 8 Family | i.MX 8QuadMax (8QM) | 8QuadPlus i.MX 8M | i.MX 8M Mini | i.MX 8M Nano PMIC Security Suspected Software Defect Yocto Project Re: Guidance for Low Power Mode on i.MX8MP Hi, 1. I would recommend Runtime PM first, use runtime PM/autosuspend for individual subsystems while Linux is running:
PCIe endpoint idle handling, need PCIe endpoint driver support: https://docs.kernel.org/power/pci.html
USB modem autosuspend / remote wakeup: linux/Documentation/driver-api/usb/power-management.rst
camera stream stop / sensor power management, should be shutdown before IDLE/SLEEP
CPU idle / DVFS
2. For short idle periods and fast wakeup, use Linux suspend-to-idle. DSM only for long idle / maximum power saving
3. For the BSP verison, recommend to use latest version.
Best Regards, Zhiming
View full article