linux-kernel - Re: [PATCH] serial-core: resume serial hardware with no_console

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Date:	Sun, 18 Oct 2009 17:49:17 +0200
From:	Stanislav Brabec <utx@...guin.cz>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	linux@....linux.org.uk, linux-kernel@...r.kernel.org,
	gregkh@...e.de, alan@...rguk.ukuu.org.uk, s.hauer@...gutronix.de,
	saxena@...top.org, Pavel Machek <pavel@....cz>
Subject: Re: [PATCH] serial-core: resume serial hardware with
	no_console_suspend

Stanislav Brabec wrote:
> Also sending a "diff -w" on the same code in the next mail for easier
> review.

Here is a "diff -w" patch without indentation changes.

Do not apply!

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index dcc7244..f1e1ab2 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2008,12 +2008,6 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 
 	mutex_lock(&port->mutex);
 
-	if (!console_suspend_enabled && uart_console(uport)) {
-		/* we're going to avoid suspending serial console */
-		mutex_unlock(&port->mutex);
-		return 0;
-	}
-
 	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
 	if (device_may_wakeup(tty_dev)) {
 		enable_irq_wake(uport->irq);
@@ -2021,12 +2015,14 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 		mutex_unlock(&port->mutex);
 		return 0;
 	}
+	if (console_suspend_enabled || !uart_console(uport))
 	uport->suspended = 1;
 
 	if (port->flags & ASYNC_INITIALIZED) {
 		const struct uart_ops *ops = uport->ops;
 		int tries;
 
+		if (console_suspend_enabled || !uart_console(uport)) {
 		set_bit(ASYNCB_SUSPENDED, &port->flags);
 		clear_bit(ASYNCB_INITIALIZED, &port->flags);
 
@@ -2035,6 +2031,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 		ops->set_mctrl(uport, 0);
 		ops->stop_rx(uport);
 		spin_unlock_irq(&uport->lock);
+		}
 
 		/*
 		 * Wait for the transmitter to empty.
@@ -2049,15 +2046,17 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 			       drv->dev_name,
 			       drv->tty_driver->name_base + uport->line);
 
+		if (console_suspend_enabled || !uart_console(uport))
 		ops->shutdown(uport);
 	}
 
 	/*
 	 * Disable the console device before suspending.
 	 */
-	if (uart_console(uport))
+	if (console_suspend_enabled && uart_console(uport))
 		console_stop(uport->cons);
 
+	if (console_suspend_enabled || !uart_console(uport))
 	uart_change_pm(state, 3);
 
 	mutex_unlock(&port->mutex);
@@ -2075,29 +2074,6 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 
 	mutex_lock(&port->mutex);
 
-	if (!console_suspend_enabled && uart_console(uport)) {
-		/* no need to resume serial console, it wasn't suspended */
-		/*
-		 * First try to use the console cflag setting.
-		 */
-		memset(&termios, 0, sizeof(struct ktermios));
-		termios.c_cflag = uport->cons->cflag;
-		/*
-		 * If that's unset, use the tty termios setting.
-		 */
-		if (termios.c_cflag == 0)
-			termios = *state->port.tty->termios;
-		else {
-			termios.c_ispeed = termios.c_ospeed =
-				tty_termios_input_baud_rate(&termios);
-			termios.c_ispeed = termios.c_ospeed =
-				tty_termios_baud_rate(&termios);
-		}
-		uport->ops->set_termios(uport, &termios, NULL);
-		mutex_unlock(&port->mutex);
-		return 0;
-	}
-
 	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
 	if (!uport->suspended && device_may_wakeup(tty_dev)) {
 		disable_irq_wake(uport->irq);
@@ -2123,6 +2099,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 		spin_lock_irq(&uport->lock);
 		ops->set_mctrl(uport, 0);
 		spin_unlock_irq(&uport->lock);
+		if (console_suspend_enabled || !uart_console(uport)) {
 		ret = ops->startup(uport);
 		if (ret == 0) {
 			uart_change_speed(state, NULL);
@@ -2139,6 +2116,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 			 */
 			uart_shutdown(state);
 		}
+		}
 
 		clear_bit(ASYNCB_SUSPENDED, &port->flags);
 	}


________________________________________________________________________
Stanislav Brabec
http://www.penguin.cz/~utx

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