Blocking sub_gpio_write()

[eps2inf]

At what point does "sub_gpio_write()" return?

1) Will it block until the GPIO lines actually transition to the desired state? Or,
2) Will it return somewhere between the issuance of the sub_gpio_write() command and the actual transition of the GPIO lines?

It appears as if the sub_gpio_write() blocks on a poll() instruction at line #1563 within libusb's handle_events() function (libusb-1.0.2). If item #2 is true, what would be the duration for the GPIO lines to transistion after the issuance of the sub_gpio_write() function?

Many thanks for a fine product, your time, and assistance towards helping me understand. Best regards.

[xol]

At what point does "sub_gpio_write()" return?

It returns after GPIO transition. GPIO transition takes about 100ns while USB frame is 1ms.