[PATCH 1/1] tty: serial: st-asc: Make the locking RT aware

[PATCH 1/1] tty: serial: st-asc: Make the locking RT aware

[Lionel Debieve]

The lock is a sleeping lock and local_irq_save() is not the
standard implementation now. Working for both -RT and non
RT.

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
---
 drivers/tty/serial/st-asc.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
index c334bcc..4889396 100644
--- a/drivers/tty/serial/st-asc.c
+++ b/drivers/tty/serial/st-asc.c
@@ -887,13 +887,12 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)
 	int locked = 1;
 	u32 intenable;
 
-	local_irq_save(flags);
 	if (port->sysrq)
 		locked = 0; /* asc_interrupt has already claimed the lock */
 	else if (oops_in_progress)
-		locked = spin_trylock(&port->lock);
+		locked = spin_trylock_irqsave(&port->lock, flags);
 	else
-		spin_lock(&port->lock);
+		spin_lock_irqsave(&port->lock, flags);
 
 	/*
 	 * Disable interrupts so we don't get the IRQ line bouncing
@@ -911,8 +910,7 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)
 	asc_out(port, ASC_INTEN, intenable);
 
 	if (locked)
-		spin_unlock(&port->lock);
-	local_irq_restore(flags);
+		spin_unlock_irqrestore(&port->lock, flags);
 }
 
 static int asc_console_setup(struct console *co, char *options)
-- 
2.7.4

Re: [PATCH 1/1] tty: serial: st-asc: Make the locking RT aware

[Patrice CHOTARD]

Hi Lionel

On 03/22/2017 06:12 PM, Lionel Debieve wrote:
> The lock is a sleeping lock and local_irq_save() is not the
> standard implementation now. Working for both -RT and non
> RT.
>
> Signed-off-by: Lionel Debieve <lionel.debieve@st.com>

Acked-by: Patrice Chotard <patrice.chotard@st.com>


> ---
>  drivers/tty/serial/st-asc.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> index c334bcc..4889396 100644
> --- a/drivers/tty/serial/st-asc.c
> +++ b/drivers/tty/serial/st-asc.c
> @@ -887,13 +887,12 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)
>  	int locked = 1;
>  	u32 intenable;
>
> -	local_irq_save(flags);
>  	if (port->sysrq)
>  		locked = 0; /* asc_interrupt has already claimed the lock */
>  	else if (oops_in_progress)
> -		locked = spin_trylock(&port->lock);
> +		locked = spin_trylock_irqsave(&port->lock, flags);
>  	else
> -		spin_lock(&port->lock);
> +		spin_lock_irqsave(&port->lock, flags);
>
>  	/*
>  	 * Disable interrupts so we don't get the IRQ line bouncing
> @@ -911,8 +910,7 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)
>  	asc_out(port, ASC_INTEN, intenable);
>
>  	if (locked)
> -		spin_unlock(&port->lock);
> -	local_irq_restore(flags);
> +		spin_unlock_irqrestore(&port->lock, flags);
>  }
>
>  static int asc_console_setup(struct console *co, char *options)
>

Re: [PATCH 1/1] tty: serial: st-asc: Make the locking RT aware

[Sebastian Andrzej Siewior]

On 2017-03-22 18:12:31 [+0100], Lionel Debieve wrote:
> The lock is a sleeping lock and local_irq_save() is not the
> standard implementation now. Working for both -RT and non
> RT.
> 
> Signed-off-by: Lionel Debieve <lionel.debieve@st.com>

Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

This is how serial8250_console_write() looks upstream, too.

Sebastian