[PATCH v2 0/3] Bluetooth: hci_bcm4377: resume after ACPI S3 and ASPM

[Andre Eikmeyer <dev@deq.rocks>]

After ACPI S3 the Bluetooth function of the BCM4377 comes back without
its firmware. Patch 2 probes it again after such a resume.

When the previous controller is still being released, the re-probe
registers the new one under another index, which runs into the probe
return check fixed in patch 1. Patch 1 is a fix on its own and goes
first.

Patch 3 is new in v2. Because of a hardware erratum the driver keeps
ASPM disabled on the whole link to the Wi-Fi and Bluetooth chip for as
long as it is bound, which holds the CPU package at PC3.
Patch 3 disables ASPM only while the firmware boots and restores it
once the firmware runs, also after the re-probe from patch 2.

The Wi-Fi function of the same chip needs the same after S3 and goes to
linux-wireless in "wifi: brcmfmac: pcie: S3 suspend and resume on the
T2 Mac chips".

Successfully ested on MacBookAir9,1 and MacBookPro15,4.

v1 [1] has not received any feedback yet.

Changes in v2:
- Add patch 3, keep ASPM off only while the firmware boots
- Patches 1 and 2 are unchanged

[1] https://lore.kernel.org/all/20261107154839.89941-1-dev@deq.rocks/

Andre Eikmeyer (3):
  Bluetooth: hci_bcm4377: treat only negative hci_register_dev() returns
    as errors
  Bluetooth: hci_bcm4377: probe again after a resume through firmware
  Bluetooth: hci_bcm4377: keep ASPM off only while the firmware boots

 drivers/bluetooth/hci_bcm4377.c | 93 +++++++++++++++++++++++++++++----
 1 file changed, 83 insertions(+), 10 deletions(-)


base-commit: 3f425f95ba3923d605f6a8b382e8fcdc59d479db