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Commit 7e1e6806 authored by Naveen Kaje's avatar Naveen Kaje Committed by Gerrit - the friendly Code Review server
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msm_serial_hs: Ensure RX side disable completes during port close 



The wakeup sequnce can alter the flush state resulting in a indefinite
wait on closing RX side of the port. Fix this by using wait_event_timeout
and disabling the RFR line.

Change-Id: I6abc2565aa08fcc04394a840ef37f62a39617b0f
Signed-off-by: default avatarNaveen Kaje <nkaje@codeaurora.org>
parent 1f2c6555

drivers/tty/serial/msm_serial_hs.c

+19 −3
Original line number Diff line number Diff line
@@ -3365,6 +3365,7 @@ static void msm_hs_shutdown(struct uart_port *uport) 
	struct circ_buf *tx_buf = &uport->state->xmit;

	struct msm_hs_tx *tx = &msm_uport->tx;

	struct sps_pipe *sps_pipe_handle = tx->cons.pipe_handle;

	unsigned long flags;



	/*

	 * cancel the hrtimer first so that
@@ -3373,6 +3374,8 @@ static void msm_hs_shutdown(struct uart_port *uport) 
	hrtimer_cancel(&msm_uport->clk_off_timer);

	flush_work(&msm_uport->clock_off_w);



	/* Stop remote side from sending data */

	msm_hs_disable_flow_control(uport);

	if (use_low_power_wakeup(msm_uport))

		irq_set_irq_wake(msm_uport->wakeup.irq, 0);
@@ -3392,20 +3395,33 @@ static void msm_hs_shutdown(struct uart_port *uport) 
	if (!ret)

		MSM_HS_WARN("Shutdown called when tx buff not empty");



	msm_hs_clock_vote(msm_uport);

	/* make sure rx tasklet finishes */

	tasklet_kill(&msm_uport->rx.tlet);

	wait_event(msm_uport->rx.wait, msm_uport->rx.flush == FLUSH_SHUTDOWN);

	if (msm_uport->rx.flush == FLUSH_STOP)

		ret = wait_event_timeout(msm_uport->rx.wait,

			msm_uport->rx.flush == FLUSH_SHUTDOWN, 500);

	else if (msm_uport->rx.flush != FLUSH_SHUTDOWN) {

		spin_lock_irqsave(&uport->lock, flags);

		msm_hs_stop_rx_locked(uport);

		spin_unlock_irqrestore(&uport->lock, flags);

		ret = wait_event_timeout(msm_uport->rx.wait,

				msm_uport->rx.flush == FLUSH_SHUTDOWN, 500);

	} else

		ret = EINPROGRESS;



	if (!ret && msm_uport->rx.flush != FLUSH_SHUTDOWN)

		MSM_HS_WARN("%s(): rx disconnect not complete", __func__);



	cancel_delayed_work_sync(&msm_uport->rx.flip_insert_work);

	flush_workqueue(msm_uport->hsuart_wq);



	msm_hs_clock_vote(msm_uport);

	mutex_lock(&msm_uport->clk_mutex);

	/* BAM Disconnect for TX */

	ret = sps_disconnect(sps_pipe_handle);

	if (ret)

		MSM_HS_ERR("%s(): sps_disconnect failed\n",

					__func__);

	WARN_ON(msm_uport->rx.flush < FLUSH_STOP);

	/* Disable the transmitter */

	msm_hs_write(uport, UART_DM_CR, UARTDM_CR_TX_DISABLE_BMSK);

	/* Disable the receiver */