| Message ID | 20240227104427.7505-1-quic_bqiang@quicinc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | wifi: ath11k: hibernation support | expand |
On 2/27/2024 6:44 PM, Baochen Qiang wrote: > 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: > > https://bugzilla.kernel.org/show_bug.cgi?id=214649 > > There already is an RFC version which has been tested by multiple users with > positive results: > > https://patchwork.kernel.org/project/linux-wireless/cover/20231127162022.518834-1-kvalo@kernel.org/ > > 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 > > https://lore.kernel.org/mhi/20231127162022.518834-1-kvalo@kernel.org/ > > 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 > > https://lore.kernel.org/all/21cd2098-97e1-4947-a5bb-a97582902ead@quicinc.com/ > > 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]. > > v3: > - skip QRTR suspend/resume if MHI device is found to be in suspend state. Forget to mention that comments on 'destroy_device' are also updated per Mani in patch 1/3. > > v2: > - add comment on why destroying the device is optional in > mhi_pm_disable_transition(). > - rename mhi_power_down_no_destroy() as mhi_power_down_keep_dev(). > - refine API description of mhi_power_down() and > mhi_power_down_keep_dev(). > - add/remove __maybe_unused to QRTR PM callbacks. > - remove '#ifdef CONFIG_PM'. > - refine commit log of patch 1/3 and 2/3. > > Baochen Qiang (3): > bus: mhi: host: add mhi_power_down_keep_dev() > net: qrtr: support suspend/hibernation > wifi: ath11k: support hibernation > > drivers/bus/mhi/host/internal.h | 4 +- > drivers/bus/mhi/host/pm.c | 42 ++++++++-- > 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 | 18 ++++- > net/qrtr/mhi.c | 46 +++++++++++ > 12 files changed, 244 insertions(+), 60 deletions(-) > > > base-commit: c39a5cfa0448f3afbee78373f16d87815a674f11