static void mhi_pm_disable_transition()

in mhi/core/pm.c [451:551]

• 73 lines of code
• 9 McCabe index (conditional complexity)

static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
{
	enum mhi_pm_state cur_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, "Processing disable transition with PM state: %s\n",
		to_mhi_pm_state_str(mhi_cntrl->pm_state));

	mutex_lock(&mhi_cntrl->pm_mutex);

	/* Trigger MHI RESET so that the device will not access host memory */
	if (!MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) {
		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 = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
				 MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 0,
				 25000);
		if (ret)
			dev_err(dev, "Device failed to clear MHI Reset\n");

		/*
		 * 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;
		free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
		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->mhi_dev->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;
	}

	/* 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);
}