[DjDeveloperr]

On a DRAM-kept wake, the Neo (J700) brings its radio link back inside the PCIe host's resume_noirq, which the whole noirq phase waits for. The bootstrap after that link-up spent 21 ms watching its retained slots. This keeps the full watch for the first bootstrap at boot and shortens it after a sleep.

• d15e15e6 PCI: apple: t8140: watch the radio slots for 2 ms after a sleep
  • After its response, the bootstrap checks that the retained slots hold still: 10 periods of 1–2 ms.
  • After a sleep, the same engine repeats a request it has already answered on this boot, and suspend_noirq reads the slots again before every sleep. So 2 periods are enough there.
  • The first bootstrap at boot keeps all 10.

Measured on the Neo (J700), 2026-11-12

Kit: this commit on cae47c00 together with #1700 and a debug-only commit (#1682's diagnostic line), aura main Stage 2. One boot, with 22 DRAM-kept sleeps in all. The "before" column is the previous kit on the same base without this commit (#1700's measurements).

	before	this PR
Bootstrap prime after a sleep (kprobes)	21.0 ms	4.3 ms
The host's radio bring-up in resume_noirq (kprobes)	123.2 ms	109.5 ms
dpm_resume_noirq phase (kprobes)	138.3 ms	124.8 ms
dpm_resume_noirq phase (power trace, median of 3)	—	124.5 ms; pcie-apple 110.2 ms

Wake timing, 8 DRAM-kept wakes, seconds from the PMU RTC alarm to the suspend exit:

• Both boots split into two groups about 45 ms apart. The gap is already there when the display firmware comes up, so it isn't this change.
• Fast group: 0.254–0.257 s here, against 0.270–0.280 s before.
• The slow group (about 0.30 s) took 5 of 8 wakes on this boot and 2 of 8 before, so the medians (0.299 against 0.279) don't show the change.

Safety, same boot:

• 10 more DRAM-kept sleeps, all DRAM-kept, with Wi-Fi (ping to the gateway) and Bluetooth up after every one.
• H.264 and HEVC encodes byte-identical after the wakes.
• No "changed outside its permitted response", "bootstrap failed", "radios did not come back" or "engine kept state" line in the boot's log.

🤖 Generated with Claude Code