TinyUSB and DFS/Light Sleep (IDFGH-12132)

[silverchris]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

Hello,
I am wondering about the correct way to handle this.
I am using an ESP32-S3
I have a self powered device that will be connected to a PC to transfer files to and from an SD card, and disconnected.

This works fine if I have DFS and light sleep off. But when turned on the computer can't configure the device.
I have been trying to find good place to take and release a esp_pm_lock.

I have tried an interrupt on the vbus_monitor_io pin, but that seems to be taken over by the USB peripheral, and doesn't seem to get called.

I have also tried it in the mount and premount callbacks, but that seems like it is too late.

What is the correct solution in this case?

[tore-espressif]

Hello @silverchris ,
During light sleep, the USB-OTG is clock-gated so it will not detect any USB event.

I can suggest the following:

• Setup esp_tinyusb with self_powered=false this way, the VBUS pin will not be owned by the USB driver
• Register wakeup event for the VBUS pin https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/sleep_modes.html#gpio-wakeup-light-sleep-only (This works only in light sleep. If you want to wake up from deep sleep you must configure ext0/1 wakeup event.)
• In you wake-up routine, you must manually trigger the VBUS connection via

esp_rom_gpio_connect_in_signal(GPIO_MATRIX_CONST_ONE_INPUT, USB_SRP_BVALID_IN_IDX, false); 

• Analogically, you can force disconnect state by

esp_rom_gpio_connect_in_signal(GPIO_MATRIX_CONST_ZERO_INPUT, USB_SRP_BVALID_IN_IDX, false); 

[silverchris]

Awesome, that works! Thanks for the help @tore-espressif !