I'm facing a problem on USB stack.
Fisrt, my configuration:
K70, MQX 4.1
I try to update usb files from MQX4.2 (not usbv2, just Usb) but problem still present.
So when USB is plugged, like done in HVAC demo, I do following:
usb_fs_ptr->DEV_FD_PTR = fopen(block_device_name, 0);
Wtih the same key, sometime return will be null, sometime return will be OK.
I debug on under layer:
_io_fopen -> _io_usb_mfs_open -> _io_usb_mfs_open_internal.
In this function, we wait a semaphore (_lwsem_wait_ticks(&info_ptr-> COMMAND_DONE, ...)
This semaphore is post in _io_usb_ctrl_callback.
When all work, in io_usb_mfs_open_interna we wait COMMAND_DONE, then the _io_usb_ctrl_callback is called (from _task_build_internal/_usb_khci_task/_usb_khci_process_tr_complete_io/_usb_ctrl_callback.
But when not working, the function _io_usb_ctrl_callback is called before the fopen call the lwsem wait.
So the post not trig the wait semaphore...
To resume, if the _lwsem_post arrive before the _lwsem_wait_ticks, we will blocked!
This semaphore behavior is Ok? Could you help me to find frome where problem comes?