Track Eurolite MK2 by actual serial number where available

[peternewman]

@aroffringa can you give this a test as mentioned in #1888 please.

This should mean the patch persists even when you plug it into a different USB port, which it won't do currently.

You should be able to see that either way as the serial number should show in the device name/description in OLA.

Originally posted by @peternewman in #1888 (comment)

[aroffringa]

Hi @peternewman , I've compiled and tested this branch. Indeed with this branch I can insert the Eurolite MK2 in a different USB port and OLA will still patch a universe to it if it existed. With the master branch this is indeed not the case; whenever I change the USB port, the universe is not patched.

As a side note, I've discovered that the Eurolite only works when it is already present when ola starts. If I insert it later, I get this log:

libs/usb/HotplugAgent.cpp:172: USB hotplug event: 2:8 @0x7f4038002e40 [add]
libs/usb/LibUsbAdaptor.cpp:53: libusb_get_string_descriptor_ascii failed: LIBUSB_ERROR_BUSY
libs/usb/LibUsbAdaptor.cpp:129: Failed to get manufacturer name
libs/usb/LibUsbAdaptor.cpp:53: libusb_get_string_descriptor_ascii failed: LIBUSB_ERROR_BUSY
libs/usb/LibUsbAdaptor.cpp:134: Failed to get product name
libs/usb/LibUsbAdaptor.cpp:53: libusb_get_string_descriptor_ascii failed: LIBUSB_ERROR_BUSY
libs/usb/LibUsbAdaptor.cpp:139: Failed to read serial number, the device probably doesn't have one
plugins/usbdmx/EuroliteProFactory.cpp:140: Connected FTDI device with serial  could be a Eurolite USB-DMX512-PRO MK2 but was ignored, because enable_eurolite_mk2 was false and its serial number was not listed specifically in eurolite_mk2_serial
plugins/usbpro/WidgetDetectorThread.cpp:215: Found potential USB Serial device at /dev/ttyUSB0
common/io/Serial.cpp:199: Acquired /var/lock/LCK..ttyUSB0
plugins/usbpro/WidgetDetectorThread.cpp:389: trying stage 0 for 0x7f4040001780
plugins/usbpro/UsbProWidgetDetector.cpp:323: USB Widget didn't respond to messages, esta id 0, device id 0
plugins/usbpro/UsbProWidgetDetector.cpp:326: Is device in USB Controller mode if it's a Goddard?
plugins/usbpro/WidgetDetectorThread.cpp:389: trying stage 1 for 0x7f4040001780
plugins/usbpro/WidgetDetectorThread.cpp:386: no more detectors to try for  0x7f4040001780
common/io/Serial.cpp:247: Released /var/lock/LCK..ttyUSB0

So somehow the libusb_get_string_descriptor_ascii fails and the device information including serial is therefore not known to OLA, causing it to not be recognized. This is not a new issue caused by the serial id check; it also doesn't work with the old method of setting enable_eurolite_mk2=true, as that results in:

libs/usb/HotplugAgent.cpp:172: USB hotplug event: 2:12 @0x7f6580002e40 [add]
libs/usb/LibUsbAdaptor.cpp:53: libusb_get_string_descriptor_ascii failed: LIBUSB_ERROR_BUSY
libs/usb/LibUsbAdaptor.cpp:129: Failed to get manufacturer name
libs/usb/LibUsbAdaptor.cpp:53: libusb_get_string_descriptor_ascii failed: LIBUSB_ERROR_BUSY
libs/usb/LibUsbAdaptor.cpp:134: Failed to get product name
libs/usb/LibUsbAdaptor.cpp:53: libusb_get_string_descriptor_ascii failed: LIBUSB_ERROR_BUSY
libs/usb/LibUsbAdaptor.cpp:139: Failed to read serial number, the device probably doesn't have one
plugins/usbdmx/EuroliteProFactory.cpp:127: Found a probable new Eurolite USB-DMX512-PRO MK2 device with serial 
libs/usb/LibUsbAdaptor.cpp:150: Manufacturer mismatch: FTDI != 

All works fine when the usb device is connected beforehand. I've therefore thus also not tested your fix by hotplugging, but using these steps:

• Connect Eurolite
• Start OLA and patch the Eurolite
• Stop OLA
• Connect Eurolite to another port
• Restart OLA and check if the universe is still patched.

So before your fix the universe isn't patched, afterwards it is.

[peternewman]

Hi @peternewman , I've compiled and tested this branch. Indeed with this branch I can insert the Eurolite MK2 in a different USB port and OLA will still patch a universe to it if it existed. With the master branch this is indeed not the case; whenever I change the USB port, the universe is not patched.

So before your fix the universe isn't patched, afterwards it is.

Great thanks. I'll merge this then, as it clearly makes things better!

As a side note, I've discovered that the Eurolite only works when it is already present when ola starts. If I insert it later, I get this log:

😢 That's a shame, lets open a new issue for that given you say its unrelated to this PR (or indeed your previous one). #1933