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Commit e50e2ac3 authored by Girish Mahadevan's avatar Girish Mahadevan
Browse files

serial: msm_geni_serial: Ensure Flow register is written during suspend 



Before shutting down the Rx engine as part of suspending the device,
ensure that the manual flow control register is written to and gets time
to take effect before proceeding with the rest of the Rx shutdown
sequence. Shutting down the Rx engine prematurely before the flow register
has had a chance to take effect could flow off the peer.

Change-Id: I7fc0d25840602e4795f720e26845092ff5ea2804
Signed-off-by: default avatarGirish Mahadevan <girishm@codeaurora.org>
parent 65ca63e7

drivers/tty/serial/msm_geni_serial.c

+9 −2
Original line number Diff line number Diff line
@@ -447,6 +447,8 @@ static void msm_geni_serial_set_mctrl(struct uart_port *uport, 
							SE_UART_MANUAL_RFR);

	/* Write to flow control must complete before return to client*/

	mb();

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

						__func__, uart_manual_rfr);

}



static const char *msm_geni_serial_get_type(struct uart_port *uport)
@@ -2540,6 +2542,8 @@ static int msm_geni_serial_runtime_suspend(struct device *dev) 
	 * set this to manual flow on.

	 */

	if (!port->manual_flow) {

		u32 geni_ios;



		uart_manual_rfr |= (UART_MANUAL_RFR_EN | UART_RFR_READY);

		geni_write_reg_nolog(uart_manual_rfr, port->uport.membase,

							SE_UART_MANUAL_RFR);
@@ -2548,8 +2552,11 @@ static int msm_geni_serial_runtime_suspend(struct device *dev) 
		 * doing a stop_rx else we could end up flowing off the peer.

		 */

		mb();

		IPC_LOG_MSG(port->ipc_log_pwr, "%s: Manual Flow ON 0x%x\n",

						 __func__, uart_manual_rfr);

		geni_ios = geni_read_reg_nolog(port->uport.membase,

								SE_GENI_IOS);

		IPC_LOG_MSG(port->ipc_log_pwr, "%s: Manual Flow ON 0x%x 0x%x\n",

					 __func__, uart_manual_rfr, geni_ios);

		udelay(10);

	}

	stop_rx_sequencer(&port->uport);

	if ((geni_status & M_GENI_CMD_ACTIVE))