static int mhi_update_channel_state()

in mhi/core/main.c [1310:1395]

• 72 lines of code
• 16 McCabe index (conditional complexity)

static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl,
				    struct mhi_chan *mhi_chan,
				    enum mhi_ch_state_type to_state)
{
	struct device *dev = &mhi_chan->mhi_dev->dev;
	enum mhi_cmd_type cmd = MHI_CMD_NOP;
	int ret;

	dev_dbg(dev, "%d: Updating channel state to: %s\n", mhi_chan->chan,
		TO_CH_STATE_TYPE_STR(to_state));

	switch (to_state) {
	case MHI_CH_STATE_TYPE_RESET:
		write_lock_irq(&mhi_chan->lock);
		if (mhi_chan->ch_state != MHI_CH_STATE_STOP &&
		    mhi_chan->ch_state != MHI_CH_STATE_ENABLED &&
		    mhi_chan->ch_state != MHI_CH_STATE_SUSPENDED) {
			write_unlock_irq(&mhi_chan->lock);
			return -EINVAL;
		}
		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
		write_unlock_irq(&mhi_chan->lock);

		cmd = MHI_CMD_RESET_CHAN;
		break;
	case MHI_CH_STATE_TYPE_STOP:
		if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
			return -EINVAL;

		cmd = MHI_CMD_STOP_CHAN;
		break;
	case MHI_CH_STATE_TYPE_START:
		if (mhi_chan->ch_state != MHI_CH_STATE_STOP &&
		    mhi_chan->ch_state != MHI_CH_STATE_DISABLED)
			return -EINVAL;

		cmd = MHI_CMD_START_CHAN;
		break;
	default:
		dev_err(dev, "%d: Channel state update to %s not allowed\n",
			mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));
		return -EINVAL;
	}

	/* bring host and device out of suspended states */
	ret = mhi_device_get_sync(mhi_cntrl->mhi_dev);
	if (ret)
		return ret;
	mhi_cntrl->runtime_get(mhi_cntrl);

	reinit_completion(&mhi_chan->completion);
	ret = mhi_send_cmd(mhi_cntrl, mhi_chan, cmd);
	if (ret) {
		dev_err(dev, "%d: Failed to send %s channel command\n",
			mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));
		goto exit_channel_update;
	}

	ret = wait_for_completion_timeout(&mhi_chan->completion,
				       msecs_to_jiffies(mhi_cntrl->timeout_ms));
	if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) {
		dev_err(dev,
			"%d: Failed to receive %s channel command completion\n",
			mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));
		ret = -EIO;
		goto exit_channel_update;
	}

	ret = 0;

	if (to_state != MHI_CH_STATE_TYPE_RESET) {
		write_lock_irq(&mhi_chan->lock);
		mhi_chan->ch_state = (to_state == MHI_CH_STATE_TYPE_START) ?
				      MHI_CH_STATE_ENABLED : MHI_CH_STATE_STOP;
		write_unlock_irq(&mhi_chan->lock);
	}

	dev_dbg(dev, "%d: Channel state change to %s successful\n",
		mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));

exit_channel_update:
	mhi_cntrl->runtime_put(mhi_cntrl);
	mhi_device_put(mhi_cntrl->mhi_dev);

	return ret;
}