From bafa91b945ac77e2e1d000e356ca819bd5f87460 Mon Sep 17 00:00:00 2001 From: Christian Poessinger Date: Mon, 8 Jun 2020 22:45:04 +0200 Subject: console: T2529: migrate from ttyUSB device to new device in /dev/serial/by-bus During testing it was discovered that there is a well known problem (we had for ethernet interfaces) also in the serial port world. They will be enumerated and mapped to /dev/ttyUSBxxx differently from boot to boot. This is especially painful on my development APU4 board which also has a Sierra Wireless MC7710 LTE module installed. The serial port will toggle between ttyUSB2 and ttyUSB5 depending on the amount of serial port extenders attached (FT4232H). The shipped udev rule (/usr/lib/udev/rules.d/60-serial.rules) partly solves this by enumerating the devices into /dev/serial/by-id folder with their name and serial number - it's a very good idea but I've found that not all of the FT4232H dongles have a serial number programmed - this leads to the situation that when you plug in two cables with both having serial number 0 - only one device symlink will appear - the previous one is always overwritten by the latter one. Derive /usr/lib/udev/rules.d/60-serial.rules and create a /dev/serial/by-bus directory and group devices by attached USB root port. --- src/migration-scripts/system/16-to-17 | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'src/migration-scripts') diff --git a/src/migration-scripts/system/16-to-17 b/src/migration-scripts/system/16-to-17 index ca3b10f49..981149d1b 100755 --- a/src/migration-scripts/system/16-to-17 +++ b/src/migration-scripts/system/16-to-17 @@ -47,6 +47,26 @@ else: if config.exists(dev_path + ['modem']): config.delete(dev_path + ['modem']) + # Only continue on USB based serial consoles + if not 'ttyUSB' in device: + continue + + # A serial console has been configured but it does no longer + # exist on the system - cleanup + if not os.path.exists(f'/dev/{device}'): + config.delete(dev_path) + continue + + # migrate from ttyUSB device to new device in /dev/serial/by-bus + for root, dirs, files in os.walk('/dev/serial/by-bus'): + for usb_device in files: + device_file = os.path.realpath(os.path.join(root, usb_device)) + # migrate to new USB device names (T2529) + if os.path.basename(device_file) == device: + config.copy(dev_path, base + ['device', usb_device]) + # Delete old USB node from config + config.delete(dev_path) + try: with open(file_name, 'w') as f: f.write(config.to_string()) -- cgit v1.2.3