This is a note to let you know that I've just added the patch titled serial: 8250_bcm7271: Save/restore RTS in suspend/resume to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-8250_bcm7271-save-restore-rts-in-suspend-resu.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 145f05b47ca85473d9035fd0feff66617f41bea1 Author: Doug Berger <opendmb@xxxxxxxxx> Date: Wed Jul 13 20:13:15 2022 -0700 serial: 8250_bcm7271: Save/restore RTS in suspend/resume [ Upstream commit 3182efd036c1b955403d131258234896cbd9fbeb ] Commit 9cabe26e65a8 ("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: 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming from S2") Signed-off-by: Doug Berger <opendmb@xxxxxxxxx> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Link: https://lore.kernel.org/r/20220714031316.404918-1-f.fainelli@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c index 9b878d023dac..8efdc271eb75 100644 --- a/drivers/tty/serial/8250/8250_bcm7271.c +++ b/drivers/tty/serial/8250/8250_bcm7271.c @@ -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; }