运行LINUX系统，使能A7核心进入低功耗，使用echo mem >/sys/power/state命令，显示 PM: suspend entry (deep)

Filesystems sync: 0.023 seconds

Freezing user space processes ... (elapsed 0.002 seconds) done.

OOM killer disabled.

Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.

printk: Suspending console(s) (use no_console_suspend to debug)

PM: dpm_run_callback(): platform_pm_suspend+0x0/0x48 returns -16

PM: Device 40017000.dac:dac@1 failed to suspend: error -16

PM: Some devices failed to suspend, or early wake event detected

OOM killer enabled.

Restarting tasks ... done.

PM: suspend exit

sh: write error: Device or resource busy

提示DAC没有进入syspend,导致休眠失败。

查看休眠结果cat /sys/kernel/debug/suspend_stats success: 0

fail: 16

failed_freeze: 0

failed_prepare: 0

failed_suspend: 16

failed_suspend_late: 0

failed_suspend_noirq: 0

failed_resume: 0

failed_resume_early: 0

failed_resume_noirq: 0、

failures:

last_failed_dev: 40017000.dac:dac@1

40017000.dac:dac@1

last_failed_errno: -16

-16

last_failed_step: suspend

suspend

DAC驱动使用的是ST原生驱动，想问一下如何解决，这块问题导致现在系统无法休眠

终于搞定了，可以休眠了，