ChibiOS Free Embedded RTOS

I added the following lines of code:
palSetPadMode(GPIOA, GPIOA_PIN8, PAL_MODE_OUTPUT_PUSHPULL);
palSetPadMode(GPIOA, GPIOA_PIN9, PAL_MODE_INPUT);
to let the pins act as input and output, reading from the documentation.
To exclude other problems, do you think that the code i wrote is good, using ...

Thank you for the reply.
I have used the osalSysPolledDelayX who call the chSysPolledDelayX function because I have a cortex-m4 but the problem is the first while loop, it never stop, meaning that there are no high level signal back.
while (!palReadPad(GPIOA, GPIOA_PIN9)) ;
This can happen because ...

Hello I have a problem to run this module, it works like this:
(1) Using IO trigger for at least 10us high level signal,
(2) The Module automatically sends eight 40 kHz and detect whether there is a
pulse signal back.
(3) IF the signal back, through high level , time of high output IO duration is ...