Commit 3182efd0 authored by Doug Berger's avatar Doug Berger Committed by Greg Kroah-Hartman
Browse files

serial: 8250_bcm7271: Save/restore RTS in suspend/resume 



Commit 9cabe26e ("serial: 8250_bcm7271: UART errors after resuming
from S2") prevented an early enabling of RTS during resume, but it did
not actively restore the RTS state after resume.

Fixes: 9cabe26e ("serial: 8250_bcm7271: UART errors after resuming from S2")
Signed-off-by: default avatarDoug Berger <opendmb@gmail.com>
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220714031316.404918-1-f.fainelli@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4f4e6703

drivers/tty/serial/8250/8250_bcm7271.c

+18 −6
Original line number Diff line number Diff line
@@ -1139,16 +1139,19 @@ static int __maybe_unused brcmuart_suspend(struct device *dev) 
	struct brcmuart_priv *priv = dev_get_drvdata(dev);

	struct uart_8250_port *up = serial8250_get_port(priv->line);

	struct uart_port *port = &up->port;



	serial8250_suspend_port(priv->line);

	clk_disable_unprepare(priv->baud_mux_clk);

	unsigned long flags;



	/*

	 * This will prevent resume from enabling RTS before the

	 *  baud rate has been resored.

	 *  baud rate has been restored.

	 */

	spin_lock_irqsave(&port->lock, flags);

	priv->saved_mctrl = port->mctrl;

	port->mctrl = 0;

	port->mctrl &= ~TIOCM_RTS;

	spin_unlock_irqrestore(&port->lock, flags);



	serial8250_suspend_port(priv->line);

	clk_disable_unprepare(priv->baud_mux_clk);



	return 0;

}
@@ -1158,6 +1161,7 @@ static int __maybe_unused brcmuart_resume(struct device *dev) 
	struct brcmuart_priv *priv = dev_get_drvdata(dev);

	struct uart_8250_port *up = serial8250_get_port(priv->line);

	struct uart_port *port = &up->port;

	unsigned long flags;

	int ret;



	ret = clk_prepare_enable(priv->baud_mux_clk);
@@ -1180,7 +1184,15 @@ static int __maybe_unused brcmuart_resume(struct device *dev) 
		start_rx_dma(serial8250_get_port(priv->line));

	}

	serial8250_resume_port(priv->line);

	port->mctrl = priv->saved_mctrl;



	if (priv->saved_mctrl & TIOCM_RTS) {

		/* Restore RTS */

		spin_lock_irqsave(&port->lock, flags);

		port->mctrl |= TIOCM_RTS;

		port->ops->set_mctrl(port, port->mctrl);

		spin_unlock_irqrestore(&port->lock, flags);

	}



	return 0;

}