From 2f2ef2c4470f83f4a9e4178070925eb250d2e9e7 Mon Sep 17 00:00:00 2001
From: Baochen Qiang <quic_bqiang@quicinc.com>
Date: Thu, 27 Jul 2023 13:11:42 +0300
Subject: [PATCH 1/8] bus: mhi: host: add mhi_power_down_no_destroy()
References: bsc#1207948
Git-commit: 2f2ef2c4470f83f4a9e4178070925eb250d2e9e7
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git
Patch-mainline: Queued in subsystem maintainer repository
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().
*/
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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(-)
--- 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,
};
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -446,7 +446,8 @@ error_mission_mode:
}
/* 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;
@@ -499,8 +500,10 @@ skip_mhi_reset:
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);
@@ -785,7 +788,10 @@ void mhi_pm_st_worker(struct work_struct
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;
@@ -1131,7 +1137,8 @@ error_exit:
}
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;
@@ -1167,14 +1174,19 @@ void mhi_power_down(struct mhi_controlle
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);
free_irq(mhi_cntrl->irq[0], mhi_cntrl);
}
-EXPORT_SYMBOL_GPL(mhi_power_down);
+EXPORT_SYMBOL_GPL(__mhi_power_down);
int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
{
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -638,12 +638,37 @@ int mhi_async_power_up(struct mhi_contro
*/
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. 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
+ */
+static inline void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
+{
+ __mhi_power_down(mhi_cntrl, graceful, true);
+}
+
/**
- * mhi_power_down - Start MHI power down sequence
+ * 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
*/
-void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful);
+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