From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Baochen Qiang <quic_bqiang@quicinc.com>
Cc: ath11k@lists.infradead.org, linux-wireless@vger.kernel.org,
linux-arm-msm@vger.kernel.org, mhi@lists.linux.dev,
davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, netdev@vger.kernel.org
Subject: Re: [PATCH v5 0/3] wifi: ath11k: hibernation support
Date: Mon, 4 Mar 2024 11:15:36 +0530 [thread overview]
Message-ID: <20240304054536.GA2647@thinkpad> (raw)
In-Reply-To: <20240304021554.77782-1-quic_bqiang@quicinc.com>
On Mon, Mar 04, 2024 at 10:15:51AM +0800, 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].
>
> v5:
> - remove Kalle's s-o-b tag in patch 1/3 per Mani.
Why are you not carrying review tags? I have reviewed the patches and provided
my tags for patches 1 and 2 in v3 and v4. Now there is no tag again in v5 :(
You cannot expect maintainers to provide review tags in each revision.
- Mani
>
> v4:
> - resend v3 as v4 to CC netdev folks. No changes in patches themselves.
>
> v3:
> - skip QRTR suspend/resume if MHI device is found to be in suspend state.
>
> 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: 48294c8a226d82c687b52b2eb90a075bbfbcb884
> --
> 2.25.1
>
--
மணிவண்ணன் சதாசிவம்
prev parent reply other threads:[~2024-03-04 5:45 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-04 2:15 [PATCH v5 0/3] wifi: ath11k: hibernation support Baochen Qiang
2024-03-04 2:15 ` [PATCH v5 1/3] bus: mhi: host: add mhi_power_down_keep_dev() Baochen Qiang
2024-03-04 2:15 ` [PATCH v5 2/3] net: qrtr: support suspend/hibernation Baochen Qiang
2024-03-04 2:15 ` [PATCH v5 3/3] wifi: ath11k: support hibernation Baochen Qiang
2024-03-04 5:45 ` Manivannan Sadhasivam [this message]
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