E: in transfer failed: -7 at AAClient about aacs HOT 2 CLOSED

Error -7 is LIBUSB_ERROR_TIMEOUT. It is hard to say why that would happen when AAClient is communicating with your mobile device. Some ideas/questions:

1. Does it work for you if you connect your mobile device to openauto directly? I once had a situation that my mobile device was very slow at establishing AA connection and I had to connect it several times before it actually started to work correctly (after that every connection was successful).
2. Look into dmesg/system logs.
3. Check if the USB cable is of good quality.
4. Use DefaultChannelHandler instead of VideoChannelHandler/InputChannelHandler in both AAServer and AAClient. This potentially provides less opportunities for errors introduced by AACS, but I don't see how this could affect this libusb error.

Please let me know if you find something out.

from aacs.

First, I looked into the dmesg logs and found out a message usbfs: process 1855 (AAClient) did not claim interface 0 before use . Using below code i got rid of this message

if (libusb_kernel_driver_active(handle, interface)) {
     if (libusb_detach_kernel_driver(handle, interface)) {}
}
libusb_claim_interface(handle, interface)

At this point my problem was still unresolved, Open E: in transfer failed: -7.

Then, I use DefaultChannelHandler instead of other handlers in both AAServer and AAClient, which solved my problem completely.

Thank You for your valuable suggestions.

from aacs.