Examples: Bad Power Management in Device Drivers

In Linux kernel, drivers are responsible to set the idle devices into low-power state. However, in our recent study of the device drivers of TI OMAP4 SoC, we found that some device drivers were doing a poor job in terms of power management. Given that every mW matters in mobile devices, we think it is worth sharing my findings. In this series, we will analyze three OMAP drivers that have poor PM implementation: drivers for GPIO, SDIO and Display Controller. We will also show how to improve PM in these drivers.

Bad PM in drivers(1)-GPIO

Bad PM in drivers(2)-SDIO

Bad PM in drivers(3)-Display Controller, failed attempts

Bad PM in drivers(3)-Display Controller, PowerAdvisor suggestions

Bad PM in drivers(4)-Watchdog timer

Delayed PM in drivers(1)-UART

Delayed PM in drivers(2)-EHCI

Delayed PM in drivers(3)-Examples in Samsung Exynos

Delayed PM in drivers(4)-Examples in Freescale i.MX

Delayed PM in drivers(4)-Examples in NVIDIA Tegra

cx/pm/main.txt · Last modified: 2017/08/14 05:20 (external edit)
 
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