[PATCH 0/3] wifi: ath11k: hibernation support

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Currently in ath11k we keep the firmware running on the WLAN device when the
network interface (wlan0) is down. The problem is that this will break
hibernation, obviously the firmware can't be running after the whole system is
powered off. To power down the ath11k firmware for suspend/hibernation some
changes both in MHI subsystem and ath11k are needed.

This patchset fixes a longstanding bug report about broken hibernation support:


There already is an RFC version which has been tested by multiple users with
positive results:


Basically the RFC version adds two APIs to MHI stack: with the first one ath11k
is able to keep MHI devices when going to suspend/hibernation, getting us rid of
the probe deferral issue when resume back. while with the second one ath11k could
manually prepare/unprepare MHI channels by itself, which is needed because QRTR
doesn't probe those channels automatically in this case.

Mani, the MHI maintainer, firstly doesn't like that version and insists that an
MHI device should be destroyed when suspend/hibernation, according to his
understanding on device driver model. See


After a long discussion Mani thought we might need a new PM callback with which
ath11k is able to wait until kernel unblocks device probe and thus MHI channels
get probed. So we came to the kernel PM list and there Mani realized that his
understanding is not correct so he finally agrees to keep MHI device during
suspend/hibernation. See


Mani also pointed out that an MHI controller driver (ath11k here) should not touch
MHI channels directly because those channels are managed by the corresponding MHI
client driver (QRTR here). To address this, we come up with this version.

Compared with that RFC version, this version adds PM callbacks in QRTR module:
suspend callback unprepares MHI channels during suspend and resume callback
prepares those channels during resume. In this way ath11k doesn't need to do
unprepare/prepare work by itself so those two APIs added in RFC version are
removed now.

The power down/up procedure requires a specific sequence in which PM callbacks
of wiphy, ath11k and QRTR are called, this is achieved by exploiting the
child-father relationship between their device struct, and also the PM framework
which separates whole suspend/resume process into several stages. Details in
patch [3/3].

Depends on:
wifi: ath11k: rearrange IRQ enable/disable in reset path
wifi: ath11k: remove MHI LOOPBACK channels
wifi: ath11k: do not dump SRNG statistics during resume
wifi: ath11k: fix warning on DMA ring capabilities event
wifi: ath11k: thermal: don't try to register multiple times

Baochen Qiang (3):
  bus: mhi: host: add mhi_power_down_no_destroy()
  net: qrtr: support suspend/hibernation
  wifi: ath11k: support hibernation

 drivers/bus/mhi/host/internal.h        |   4 +-
 drivers/bus/mhi/host/pm.c              |  36 +++++++--
 drivers/net/wireless/ath/ath11k/ahb.c  |   6 +-
 drivers/net/wireless/ath/ath11k/core.c | 105 +++++++++++++++++--------
 drivers/net/wireless/ath/ath11k/core.h |   6 +-
 drivers/net/wireless/ath/ath11k/hif.h  |  14 +++-
 drivers/net/wireless/ath/ath11k/mhi.c  |  12 ++-
 drivers/net/wireless/ath/ath11k/mhi.h  |   5 +-
 drivers/net/wireless/ath/ath11k/pci.c  |  44 +++++++++--
 drivers/net/wireless/ath/ath11k/qmi.c  |   2 +-
 include/linux/mhi.h                    |  15 +++-
 net/qrtr/mhi.c                         |  29 +++++++
 12 files changed, 218 insertions(+), 60 deletions(-)

base-commit: 707e306f3573fa321ae197d77366578e4566cff5
prerequisite-patch-id: d3f76112f9a55195c71459e0edf3a4ecf8af9181
prerequisite-patch-id: 340d15aad1d3c1c3c93d9d996e1c96226c8bad8f
prerequisite-patch-id: 98cdd37a68df4f651a065145e946d92c43be799e
prerequisite-patch-id: a19ed13af0c894b7f9b22cedc99029991f48e47c
prerequisite-patch-id: b5ad50fae6167c7c2b60cc063a8d460f7ddd4997

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