Choice excerpts from dmesg:

[    0.000000] Atom PSE erratum detected, BIOS microcode update
recommended

[    0.000000] ACPI: BIOS bug: multiple APIC/MADT found, using 0
[    0.000000] ACPI: If "acpi_apic_instance=2" works better, notify 
[email protected]

[    0.180781] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored

I'd suggest seeing if there's a BIOS update available for your system,
which may or may not improve suspend/resume functionality a bit.
Especially if its taking more than a minute to resume.

However, that aside, looking at both the dib0700 driver and the ftdi_sio
driver, I noticed they lack suspend or resume functions entirely. The
ftdi_sio driver may have the default usb-serial suspend routine wired up
to it somehow though. But anyway, I'm not sure if the usb core is
possibly behaving as expected, disconnecting the devices, rather than
suspending them, or if its the usb chipset not suspending properly.

The incremented ttyUSBx device makes some degree of sense though. If
lircd has an active client (such as irxevent) at suspend time, then the
IR device (/dev/ttyUSB0) will be open, in which case, it can't be fully
removed. Thus, when the device is reconnected, it gets ttyUSB1, as
there's still a lingering reference to ttyUSB0. No clients, 0 gets fully
freed up, and can be allocated again. I'll have to see about getting
some ftdi usb IR hardware one of these days to get a better
understanding of what's going on. I do stand by the assertion that lirc
isn't actually doing anything wrong here though. :)

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https://bugs.launchpad.net/bugs/359356

Title:
  USB device attached to different ttyUSB after resume from suspend to
  RAM

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