What causes the long resume time:

The fwts suspend/1_suspend-time-check failure (~6.9s resume, threshold 5.0s) is 
not caused by the kernel PM path itself. Kernel device resume completes in 
~109ms:
PM: resume of devices complete after 105.797 msecs
PM: suspend exit

The 6-7 seconds are consumed after PM: suspend exit, by the 
/lib/systemd/system-sleep/hdparm post-resume hook (which calls 
/usr/lib/pm-utils/power.d/95hdparm-apm resume). That script runs hdparm -B 254 
synchronously on each SATA disk. The hdparm ioctl blocks in the kernel because 
libata's Error Handler (EH) holds a SCSI queue freeze on the ata3 port while it 
spins the disk back up from STANDBY:
PM: suspend exit
ata3: link is slow to respond, please be patient (ready=0)   ← +5.2s
ata3: SATA link up 6.0 Gbps
ata3.00: configured for UDMA/133                             ← EH done, queue 
unfrozen
systemd-suspend.service: Deactivated successfully.           ← hook finally 
exits
fwts: FWTS_RESUME                                            ← 6.9s total

fwts measures the resume time from when systemd-suspend.service
deactivates. Because the backgrounded/blocked hdparm keeps that
service's cgroup alive, fwts only records "resume complete" once the
disk finishes spinning up.

Booting with nohdparm on the kernel cmdline (which makes 95hdparm-apm
exit immediately) drops the resume time to ~0.40s and the test PASSES on
both 6.11 and 6.17.

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https://bugs.launchpad.net/bugs/2160187

Title:
  Suspend resume time is longer than the threshold on Dell Pro Tower
  QCT1255.

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