From: Mayank Rana <quic_mrana@quicinc.com>
To: Kalle Valo <kvalo@kernel.org>, <mhi@lists.linux.dev>
Cc: <ath11k@lists.infradead.org>, <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH RFC 1/8] bus: mhi: host: add mhi_power_down_no_destroy()
Date: Mon, 13 Nov 2023 17:26:09 -0800 [thread overview]
Message-ID: <e0df4f22-c867-410b-8868-5a8f2e55f9c6@quicinc.com> (raw)
In-Reply-To: <20231110102202.3168243-2-kvalo@kernel.org>
On 11/10/2023 2:21 AM, Kalle Valo wrote:
> From: Baochen Qiang <quic_bqiang@quicinc.com>
>
> If ath11k tries to call mhi_power_up() during resume it fails:
>
> ath11k_pci 0000:06:00.0: timeout while waiting for restart complete
>
> This happens because when calling mhi_power_up() the MHI subsystem eventually
> calls device_add() from mhi_create_devices() but the device creation is
> deferred:
>
> mhi mhi0_IPCR: Driver qcom_mhi_qrtr force probe deferral
>
> The reason for deferring device creation is explained in dpm_prepare():
>
> /*
> * It is unsafe if probing of devices will happen during suspend or
> * hibernation and system behavior will be unpredictable in this case.
> * So, let's prohibit device's probing here and defer their probes
> * instead. The normal behavior will be restored in dpm_complete().
> */
have you consider registering for pm_notifier callback specifically for
PM_POST_HIBERNATION (Documentation/power/notifiers.txt), and then making
decision of calling MHI power up sequence which would make sure that
created device based driver probe() is completed.
>
> Because the device probe is deferred, the qcom_mhi_qrtr_probe() is not called and
> qcom_mhi_qrtr_dl_callback() fails silently as qdev is zero:
>
> static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,
> struct mhi_result *mhi_res)
> {
> struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
> int rc;
>
> if (!qdev || mhi_res->transaction_status)
> return;
>
> So what this means that QRTR is not delivering messages and the QMI connection
> is not working between ath11k and the firmware, resulting a failure in firmware
> initialisation.
>
> To fix this add new function mhi_power_down_no_destroy() which does not destroy
> the devices during power down. This way mhi_power_up() can be called during
> resume and we can get ath11k hibernation working with the following patches.
>
> Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30
>
> Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
> ---
> drivers/bus/mhi/host/internal.h | 1 +
> drivers/bus/mhi/host/pm.c | 26 +++++++++++++++++++-------
> include/linux/mhi.h | 29 +++++++++++++++++++++++++++--
> 3 files changed, 47 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
> index 2e139e76de4c..d1033af285e2 100644
> --- a/drivers/bus/mhi/host/internal.h
> +++ b/drivers/bus/mhi/host/internal.h
> @@ -69,6 +69,7 @@ enum dev_st_transition {
> DEV_ST_TRANSITION_FP,
> DEV_ST_TRANSITION_SYS_ERR,
> DEV_ST_TRANSITION_DISABLE,
> + DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE,
> DEV_ST_TRANSITION_MAX,
> };
>
> diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
> index 8a4362d75fc4..e0e429adbda6 100644
> --- a/drivers/bus/mhi/host/pm.c
> +++ b/drivers/bus/mhi/host/pm.c
> @@ -453,7 +453,8 @@ static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl)
> }
>
> /* Handle shutdown transitions */
> -static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
> +static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
> + bool destroy_device)
> {
> enum mhi_pm_state cur_state;
> struct mhi_event *mhi_event;
> @@ -515,8 +516,10 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
> dev_dbg(dev, "Waiting for all pending threads to complete\n");
> wake_up_all(&mhi_cntrl->state_event);
>
> - dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
> - device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device);
> + if (destroy_device) {
> + dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
> + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device);
> + }
>
> mutex_lock(&mhi_cntrl->pm_mutex);
>
> @@ -801,7 +804,10 @@ void mhi_pm_st_worker(struct work_struct *work)
> mhi_pm_sys_error_transition(mhi_cntrl);
> break;
> case DEV_ST_TRANSITION_DISABLE:
> - mhi_pm_disable_transition(mhi_cntrl);
> + mhi_pm_disable_transition(mhi_cntrl, false);
> + break;
> + case DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE:
> + mhi_pm_disable_transition(mhi_cntrl, true);
> break;
> default:
> break;
> @@ -1154,7 +1160,8 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
> }
> EXPORT_SYMBOL_GPL(mhi_async_power_up);
>
> -void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
> +void __mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful,
> + bool destroy_device)
> {
> enum mhi_pm_state cur_state, transition_state;
> struct device *dev = &mhi_cntrl->mhi_dev->dev;
> @@ -1190,14 +1197,19 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
> write_unlock_irq(&mhi_cntrl->pm_lock);
> mutex_unlock(&mhi_cntrl->pm_mutex);
>
> - mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_DISABLE);
> + if (destroy_device)
> + mhi_queue_state_transition(mhi_cntrl,
> + DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE);
> + else
> + mhi_queue_state_transition(mhi_cntrl,
> + DEV_ST_TRANSITION_DISABLE);
>
> /* Wait for shutdown to complete */
> flush_work(&mhi_cntrl->st_worker);
>
> disable_irq(mhi_cntrl->irq[0]);
> }
> -EXPORT_SYMBOL_GPL(mhi_power_down);
> +EXPORT_SYMBOL_GPL(__mhi_power_down);
>
> int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
> {
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index 039943ec4d4e..85edc9c5df88 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -644,12 +644,37 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl);
> */
> int mhi_sync_power_up(struct mhi_controller *mhi_cntrl);
>
> +void __mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful,
> + bool destroy_device);
> +
> /**
> - * mhi_power_down - Start MHI power down sequence
> + * mhi_power_down - Start MHI power down sequence. See also
> + * mhi_power_down_no_destroy() which is a variant of this for suspend.
> + *
> * @mhi_cntrl: MHI controller
> * @graceful: Link is still accessible, so do a graceful shutdown process
> */
> -void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful);
> +static inline void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
> +{
> + __mhi_power_down(mhi_cntrl, graceful, true);
> +}
> +
> +/**
> + * mhi_power_down_no_destroy - Start MHI power down sequence but don't
> + * destroy struct devices. This is a variant for mhi_power_down() and is a
> + * workaround to make it possible to use mhi_power_up() in a resume
> + * handler. When using this variant the caller must also call
> + * mhi_prepare_all_for_transfer_autoqueue() and
> + * mhi_unprepare_all_from_transfer().
> + *
> + * @mhi_cntrl: MHI controller
> + * @graceful: Link is still accessible, so do a graceful shutdown process
> + */
> +static inline void mhi_power_down_no_destroy(struct mhi_controller *mhi_cntrl,
> + bool graceful)
> +{
> + __mhi_power_down(mhi_cntrl, graceful, false);
> +}
>
> /**
> * mhi_unprepare_after_power_down - Free any allocated memory after power down
--
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next prev parent reply other threads:[~2023-11-14 1:27 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-10 10:21 [PATCH RFC 0/8] wifi: ath11k: hibernation support Kalle Valo
2023-11-10 10:21 ` [PATCH RFC 1/8] bus: mhi: host: add mhi_power_down_no_destroy() Kalle Valo
2023-11-14 1:26 ` Mayank Rana [this message]
2023-11-10 10:21 ` [PATCH RFC 2/8] bus: mhi: host: add new interfaces to handle MHI channels directly Kalle Valo
2023-11-10 17:14 ` Jeffrey Hugo
2023-11-12 3:59 ` Baochen Qiang
2023-11-12 16:18 ` Jeffrey Hugo
2023-11-13 0:32 ` Baochen Qiang
2023-11-10 10:21 ` [PATCH RFC 3/8] wifi: ath11k: handle irq enable/disable in several code path Kalle Valo
2023-11-10 10:21 ` [PATCH RFC 4/8] wifi: ath11k: remove MHI LOOPBACK channels Kalle Valo
2023-11-10 16:54 ` Jeffrey Hugo
2023-11-12 4:24 ` Baochen Qiang
2023-11-12 16:15 ` Jeffrey Hugo
2023-11-13 0:30 ` Baochen Qiang
2023-11-13 14:15 ` Kalle Valo
2023-11-13 14:26 ` Jeffrey Hugo
2023-11-13 15:04 ` Kalle Valo
2023-11-10 10:21 ` [PATCH RFC 5/8] wifi: ath11k: do not dump SRNG statistics during resume Kalle Valo
2023-11-10 10:22 ` [PATCH RFC 6/8] wifi: ath11k: fix warning on DMA ring capabilities event Kalle Valo
2023-11-10 10:22 ` [PATCH RFC 7/8] wifi: ath11k: thermal: don't try to register multiple times Kalle Valo
2023-11-10 10:22 ` [PATCH RFC 8/8] wifi: ath11k: support hibernation Kalle Valo
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