[求助] STM32 USB Host suspend/resume

STM32作为usb host，需要suspend和resume, 查看了手册，suspend需要设置PSUSP bit in OTG_HS_HPRT，resume需要设置PRES bit in OTG_HS_HPRT，现在是设置suspend后程序还在运行，sof不发了，应该是正常的，但是resume不能恢复sof了
“If the Suspended state is exited on the host initiative, the application must set the port
resume bit to start resume signaling on the host port, monitor the resume window duration
and then clear the port resume bit.”
resume的时间从5ms到20ms都不行，请各位帮忙指点一下