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Commit 235585bd authored by Chandana Kishori Chiluveru's avatar Chandana Kishori Chiluveru
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serial: msm_geni_serial: Do not change Flow control from termios 



This change ensures UART driver doesn't control the flow lines when
baud change is requested. UART client must ensure that peer device
is flowed off before requesting the baud change.

If UART driver control the Flow lines it may happen that after baud
rate change, immediately driver decides to Flow it ON which may have
side effect to client if it doesn't really intend to receive anything
from ther peer side.

This way we are ensuring the window of baud change is controlled by
client and not disturbed by the driver.

Change-Id: Id88ae03dc8a81830393597e72109ee7015cb6226
Signed-off-by: default avatarMukesh Kumar Savaliya <msavaliy@codeaurora.org>
Signed-off-by: default avatarChandana Kishori Chiluveru <cchiluve@codeaurora.org>
parent aac28acd

drivers/tty/serial/msm_geni_serial.c

+6 −6
Original line number Diff line number Diff line
@@ -1430,7 +1430,6 @@ static int stop_rx_sequencer(struct uart_port *uport) 
	}



	if (!uart_console(uport)) {

		msm_geni_serial_set_manual_flow(false, port);

		/*

		 * Wait for the stale timeout to happen if there

		 * is any data pending in the rx fifo.
@@ -1547,9 +1546,6 @@ static int stop_rx_sequencer(struct uart_port *uport) 
	port->s_cmd = false;



exit_rx_seq:

	if (!uart_console(uport))

		msm_geni_serial_set_manual_flow(true, port);



	geni_status = geni_read_reg_nolog(uport->membase, SE_GENI_STATUS);

	IPC_LOG_MSG(port->ipc_log_misc, "%s: End 0x%x dma_dbg:0x%x\n",

		    __func__, geni_status,
@@ -3304,9 +3300,10 @@ static int msm_geni_serial_runtime_suspend(struct device *dev) 
							SE_GENI_STATUS);



	IPC_LOG_MSG(port->ipc_log_pwr, "%s: Start\n", __func__);

	/* Flow off from UART */

	msm_geni_serial_set_manual_flow(false, port);

	wait_for_transfers_inflight(&port->uport);

	/*

	 * Manual RFR On.

	 * Stop Rx.

	 * Disable Interrupt

	 * Resources off
@@ -3315,6 +3312,8 @@ static int msm_geni_serial_runtime_suspend(struct device *dev) 
	if (ret) {

		IPC_LOG_MSG(port->ipc_log_pwr, "%s: stop rx failed %d\n",

							__func__, ret);

		/* Flow on from UART */

		msm_geni_serial_allow_rx(port);

		return -EBUSY;

	}
@@ -3325,7 +3324,8 @@ static int msm_geni_serial_runtime_suspend(struct device *dev) 
	disable_irq(port->uport.irq);



	/*

	 * Above stop_rx disabled the flow so we need to enable it here

	 * Flow on from UART

	 * Above before stop_rx disabled the flow so we need to enable it here

	 * Make sure wake up interrupt is enabled before RFR is made low

	 */

	msm_geni_serial_allow_rx(port);