From: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
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@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
---
drivers/bus/mhi/host/init.c | 1 +
drivers/bus/mhi/host/internal.h | 1 +
drivers/bus/mhi/host/pm.c | 26 +++++++++++++++++++-------
include/linux/mhi.h | 29 +++++++++++++++++++++++++++--
4 files changed, 48 insertions(+), 9 deletions(-)
diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index 65ceac1837f9..e626b03ffafa 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -43,6 +43,7 @@ const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
[DEV_ST_TRANSITION_FP] = "FLASH PROGRAMMER",
[DEV_ST_TRANSITION_SYS_ERR] = "SYS ERROR",
[DEV_ST_TRANSITION_DISABLE] = "DISABLE",
+ [DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE] = "DISABLE (DESTROY DEVICE)",
};
const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX] = {
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 30ac415a3000..3f45c9c447bd 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 a2f2feef1476..8833b0248393 100644
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -458,7 +458,8 @@ 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;
@@ -520,8 +521,10 @@ 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);
@@ -806,7 +809,10 @@ 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;
@@ -1160,7 +1166,8 @@ 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;
@@ -1196,14 +1203,19 @@ 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 d0f9b522f328..ae092bc8b97e 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -648,12 +648,37 @@ 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
--
2.39.2
