MTP event on Windows undetected (MTP_EVENT_XXX)

[Tiarkhog]

Hello. I’m using tinyUsb for a MTP stack embedded in a stm32L4.
I’m facing an issue : Windows doesn’t reload the files nor call MTP_OP_GET_OBJECT_HANDLES or MTP_OP_GET_OBJECT_INFO. I’m wondering how should I do.
I guess I have to use tud_mtp_event_send, isn’t it ? How do I can get the session_id (which seems to be 0 all the time) and the transaction_id ? What parameters should be set or how should this function must be used ?
The stm32 is writing some files, and I want is windows to download the whole file and not just what it kept in cache. I also would like windows to detect a new file if the stm32 create a new one

In tusb_config.h, it seems that only MTP_EVENT_OBJECT_ADDED is set. I added the other anyway.

Thanks in advance. Have a good day.
Thanks for this tinyusb stack.

[KDWT]

I'm currently working on the same problem. Unfortunately, my host doesn't check for new files either. For example,
I want to inform the host that a file has been created. If the file was created successfully, I call the function

trigger_event(MTP_EVENT_OBJECT_ADDED, theNewHandle);

with

bool trigger_event(uint16_t event_code, uint32_t handle)
{
    if (!tud_mtp_mounted())
    {
        return false;
    }

    mtp_event_t evt = {
        .code = event_code,
        .session_id = UINT32_MAX,
        .transaction_id = 0,
        .params = { handle, 0, 0}
    };

    return tud_mtp_event_send(&evt);
}

session_id is UINT32_MAX because MTP specification v1.0 descripted: "If this event is relevant to all current sessions,
it shall contain 0xFFFFFFFF". The function returns true



In the tusb_config.h I have:

#define CFG_TUD_MTP_DEVICEINFO_SUPPORTED_EVENTS \
MTP_EVENT_OBJECT_ADDED, \
MTP_EVENT_OBJECT_REMOVED, \
MTP_EVENT_OBJECT_INFO_CHANGED

Since this also doesn't work, I'm wondering if something is missing or if the function is faulty.


Using STM32L4 as the device, TinyUSB 0.20.0 and Windows 11 as the host