[Feature Request] ath12k: Optimize s2idle wake latency / Implement Fast Resume for WCN785x

[Paolo Ferraris]

Hello ath12k maintainers and developers,
I am writing to respectfully request an optimization for the  ath12k
firmware/driver regarding the resume latency from  s2idle  on modern
Intel platforms.
Hardware Details:
  • Laptop: HP Spectre 16 (Intel Meteor Lake Ultra 7 155H)
  • Wi-Fi Module: Qualcomm WCN785x Wi-Fi 7 (FastConnect 7800)
  • Kernel: Linux 7.0 (Arch Linux)
The Issue
When the laptop resumes from  s2 idle  sleep, the WCN785x takes a
consistent 10 to 15 seconds to establish a connection. Based on  dmesg
 logs, it appears the firmware undergoes a full cold-boot sequence (
fw_version  is re-logged) followed by a lengthy passive regulatory
sweep of the channels before allowing Authentication

Diagnosis & Isolation:
To ensure this was not a motherboard ACPI issue or an Intel PCIe
dropout bug (like the  0xffffffff  ASPM bug seen on some Intel cards),
we physically swapped the Wifi module on this exact same motherboard
to a MediaTek MT7922 (Wi-Fi 6E). The MT7922 resumed and authenticated
almost instantly upon waking from  s2idle . This confirms that the HP
BIOS and the Linux kernel are handling the PCIe wake states correctly,
and the latency is strictly isolated to the  ath12k  firmware
initialization and scanning routine.

Feature Request:
Would it be possible for the Qualcomm firmware team to implement "Scan
Caching" or a "Fast Resume" state for  s2idle  in a future firmware
release? Ideally, allowing the chip to cache the connected AP's
channel before sleep to bypass the massive 15-second passive sweep
upon waking.
Thank you very much for your hard work on the ath12k driver!

Best regards,
Paolo Ferraris