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bus: mhi: core: Separate system error and power down handling 

Currently, there exist a set of if...else statements in the
mhi_pm_disable_transition() function which make handling system
error and disable transitions differently complex. To make that
cleaner and facilitate differences in behavior, separate these
two transitions for MHI host.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
This commit is contained in:
Bhaumik Bhatt 2020-11-09 12:47:29 -08:00 committed by Manivannan Sadhasivam
parent 40c3127187
commit 556bbb442b
No known key found for this signature in database
GPG Key ID: 559F11E6FE91CEF5
1 changed files with 137 additions and 22 deletions
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159
drivers/bus/mhi/core/pm.c
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@ -444,7 +444,7 @@ static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl)
return ret;
}
/* Handle SYS_ERR and Shutdown transitions */
/* Handle shutdown transitions */
static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
enum mhi_pm_state transition_state)
{
@ -460,10 +460,6 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
to_mhi_pm_state_str(mhi_cntrl->pm_state),
to_mhi_pm_state_str(transition_state));
/* We must notify MHI control driver so it can clean up first */
if (transition_state == MHI_PM_SYS_ERR_PROCESS)
mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR);
mutex_lock(&mhi_cntrl->pm_mutex);
write_lock_irq(&mhi_cntrl->pm_lock);
prev_state = mhi_cntrl->pm_state;
@ -502,11 +498,8 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
MHICTRL_RESET_SHIFT,
&in_reset) ||
!in_reset, timeout);
if ((!ret || in_reset) && cur_state == MHI_PM_SYS_ERR_PROCESS) {
if (!ret || in_reset)
dev_err(dev, "Device failed to exit MHI Reset state\n");
mutex_unlock(&mhi_cntrl->pm_mutex);
return;
}
/*
* Device will clear BHI_INTVEC as a part of RESET processing,
@ -566,19 +559,142 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
er_ctxt->wp = er_ctxt->rbase;
}
if (cur_state == MHI_PM_SYS_ERR_PROCESS) {
mhi_ready_state_transition(mhi_cntrl);
} else {
/* Move to disable state */
write_lock_irq(&mhi_cntrl->pm_lock);
cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE);
write_unlock_irq(&mhi_cntrl->pm_lock);
if (unlikely(cur_state != MHI_PM_DISABLE))
dev_err(dev, "Error moving from PM state: %s to: %s\n",
to_mhi_pm_state_str(cur_state),
to_mhi_pm_state_str(MHI_PM_DISABLE));
/* Move to disable state */
write_lock_irq(&mhi_cntrl->pm_lock);
cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE);
write_unlock_irq(&mhi_cntrl->pm_lock);
if (unlikely(cur_state != MHI_PM_DISABLE))
dev_err(dev, "Error moving from PM state: %s to: %s\n",
to_mhi_pm_state_str(cur_state),
to_mhi_pm_state_str(MHI_PM_DISABLE));
dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
to_mhi_pm_state_str(mhi_cntrl->pm_state),
TO_MHI_STATE_STR(mhi_cntrl->dev_state));
mutex_unlock(&mhi_cntrl->pm_mutex);
}
/* Handle system error transitions */
static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl)
{
enum mhi_pm_state cur_state, prev_state;
struct mhi_event *mhi_event;
struct mhi_cmd_ctxt *cmd_ctxt;
struct mhi_cmd *mhi_cmd;
struct mhi_event_ctxt *er_ctxt;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
int ret, i;
dev_dbg(dev, "Transitioning from PM state: %s to: %s\n",
to_mhi_pm_state_str(mhi_cntrl->pm_state),
to_mhi_pm_state_str(MHI_PM_SYS_ERR_PROCESS));
/* We must notify MHI control driver so it can clean up first */
mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR);
mutex_lock(&mhi_cntrl->pm_mutex);
write_lock_irq(&mhi_cntrl->pm_lock);
prev_state = mhi_cntrl->pm_state;
cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_SYS_ERR_PROCESS);
write_unlock_irq(&mhi_cntrl->pm_lock);
if (cur_state != MHI_PM_SYS_ERR_PROCESS) {
dev_err(dev, "Failed to transition from PM state: %s to: %s\n",
to_mhi_pm_state_str(cur_state),
to_mhi_pm_state_str(MHI_PM_SYS_ERR_PROCESS));
goto exit_sys_error_transition;
}
mhi_cntrl->ee = MHI_EE_DISABLE_TRANSITION;
mhi_cntrl->dev_state = MHI_STATE_RESET;
/* Wake up threads waiting for state transition */
wake_up_all(&mhi_cntrl->state_event);
/* Trigger MHI RESET so that the device will not access host memory */
if (MHI_REG_ACCESS_VALID(prev_state)) {
u32 in_reset = -1;
unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms);
dev_dbg(dev, "Triggering MHI Reset in device\n");
mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
/* Wait for the reset bit to be cleared by the device */
ret = wait_event_timeout(mhi_cntrl->state_event,
mhi_read_reg_field(mhi_cntrl,
mhi_cntrl->regs,
MHICTRL,
MHICTRL_RESET_MASK,
MHICTRL_RESET_SHIFT,
&in_reset) ||
!in_reset, timeout);
if (!ret || in_reset) {
dev_err(dev, "Device failed to exit MHI Reset state\n");
goto exit_sys_error_transition;
}
/*
* Device will clear BHI_INTVEC as a part of RESET processing,
* hence re-program it
*/
mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
}
dev_dbg(dev,
"Waiting for all pending event ring processing to complete\n");
mhi_event = mhi_cntrl->mhi_event;
for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
if (mhi_event->offload_ev)
continue;
tasklet_kill(&mhi_event->task);
}
/* Release lock and wait for all pending threads to complete */
mutex_unlock(&mhi_cntrl->pm_mutex);
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->cntrl_dev, NULL, mhi_destroy_device);
mutex_lock(&mhi_cntrl->pm_mutex);
WARN_ON(atomic_read(&mhi_cntrl->dev_wake));
WARN_ON(atomic_read(&mhi_cntrl->pending_pkts));
/* Reset the ev rings and cmd rings */
dev_dbg(dev, "Resetting EV CTXT and CMD CTXT\n");
mhi_cmd = mhi_cntrl->mhi_cmd;
cmd_ctxt = mhi_cntrl->mhi_ctxt->cmd_ctxt;
for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
struct mhi_ring *ring = &mhi_cmd->ring;
ring->rp = ring->base;
ring->wp = ring->base;
cmd_ctxt->rp = cmd_ctxt->rbase;
cmd_ctxt->wp = cmd_ctxt->rbase;
}
mhi_event = mhi_cntrl->mhi_event;
er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
mhi_event++) {
struct mhi_ring *ring = &mhi_event->ring;
/* Skip offload events */
if (mhi_event->offload_ev)
continue;
ring->rp = ring->base;
ring->wp = ring->base;
er_ctxt->rp = er_ctxt->rbase;
er_ctxt->wp = er_ctxt->rbase;
}
mhi_ready_state_transition(mhi_cntrl);
exit_sys_error_transition:
dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
to_mhi_pm_state_str(mhi_cntrl->pm_state),
TO_MHI_STATE_STR(mhi_cntrl->dev_state));
@ -666,8 +782,7 @@ void mhi_pm_st_worker(struct work_struct *work)
mhi_ready_state_transition(mhi_cntrl);
break;
case DEV_ST_TRANSITION_SYS_ERR:
mhi_pm_disable_transition
(mhi_cntrl, MHI_PM_SYS_ERR_PROCESS);
mhi_pm_sys_error_transition(mhi_cntrl);
break;
case DEV_ST_TRANSITION_DISABLE:
mhi_pm_disable_transition