STM32MP157D提示DAC没有进入syspend,导致休眠失败怎么解决？

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_statssuccess: 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