After a cold boot the EM160R-GL often drops off the PCIe link 10-20s
after probe ("Unable to change power state from D3cold to D0", config
space reads all-ones) and never brings up its wwan ports. Until now
only a hibernate/resume cycle brought it back.
An ACPI _RST through the PCI reset attribute does the same at runtime.
The rescan after it catches the firmware mid-boot, under the generic
Qualcomm ID 17cb:0304, which has no FCC unlock script, so ModemManager
fails with "Couldn't set operating mode". A second rescan once the
firmware is up gets 1eac:100d back and the modem enables normally.
The service does nothing if wwan ports show up within 60s of boot.
The recovery sequence was verified by hand on 7.2.11; the service has
not yet run it on a real cold boot.
Assisted-by: Claude:opus-5-5
Sergei Poljanski
285933d22c