mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Optimize i8259 code a bit.
Date: Sun, 28 Oct 2007 17:54:15 +0100 (CET)	[thread overview]
Message-ID: <alpine.LFD.0.9999.0710281753000.3186@localhost.localdomain> (raw)
In-Reply-To: <20071028231145.GA9515@linux-mips.org>

On Sun, 28 Oct 2007, Ralf Baechle wrote:

> The timer code always calls the clock_event_device set_net_event and
> set_mode methods with interrupts disabled, so no need to use
> spin_lock_irqsave / spin_unlock_irqrestore for those.

Good point,

Acked-by:Thomas Gleixner <tglx@linutronix.de>


> diff --git a/arch/mips/kernel/i8253.c b/arch/mips/kernel/i8253.c
> index 5d9830d..1b54674 100644
> --- a/arch/mips/kernel/i8253.c
> +++ b/arch/mips/kernel/i8253.c
> @@ -23,9 +23,7 @@ static DEFINE_SPINLOCK(i8253_lock);
>  static void init_pit_timer(enum clock_event_mode mode,
>  			   struct clock_event_device *evt)
>  {
> -	unsigned long flags;
> -
> -	spin_lock_irqsave(&i8253_lock, flags);
> +	spin_lock(&i8253_lock);
>  
>  	switch(mode) {
>  	case CLOCK_EVT_MODE_PERIODIC:
> @@ -54,7 +52,7 @@ static void init_pit_timer(enum clock_event_mode mode,
>  		/* Nothing to do here */
>  		break;
>  	}
> -	spin_unlock_irqrestore(&i8253_lock, flags);
> +	spin_unlock(&i8253_lock);
>  }
>  
>  /*
> @@ -64,12 +62,10 @@ static void init_pit_timer(enum clock_event_mode mode,
>   */
>  static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
>  {
> -	unsigned long flags;
> -
> -	spin_lock_irqsave(&i8253_lock, flags);
> +	spin_lock(&i8253_lock);
>  	outb_p(delta & 0xff , PIT_CH0);	/* LSB */
>  	outb(delta >> 8 , PIT_CH0);	/* MSB */
> -	spin_unlock_irqrestore(&i8253_lock, flags);
> +	spin_unlock(&i8253_lock);
>  
>  	return 0;
>  }
> diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
> index a42c807..5246515 100644
> --- a/arch/x86/kernel/i8253.c
> +++ b/arch/x86/kernel/i8253.c
> @@ -31,9 +31,7 @@ struct clock_event_device *global_clock_event;
>  static void init_pit_timer(enum clock_event_mode mode,
>  			   struct clock_event_device *evt)
>  {
> -	unsigned long flags;
> -
> -	spin_lock_irqsave(&i8253_lock, flags);
> +	spin_lock(&i8253_lock);
>  
>  	switch(mode) {
>  	case CLOCK_EVT_MODE_PERIODIC:
> @@ -62,7 +60,7 @@ static void init_pit_timer(enum clock_event_mode mode,
>  		/* Nothing to do here */
>  		break;
>  	}
> -	spin_unlock_irqrestore(&i8253_lock, flags);
> +	spin_unlock(&i8253_lock);
>  }
>  
>  /*
> @@ -72,12 +70,10 @@ static void init_pit_timer(enum clock_event_mode mode,
>   */
>  static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
>  {
> -	unsigned long flags;
> -
> -	spin_lock_irqsave(&i8253_lock, flags);
> +	spin_lock(&i8253_lock);
>  	outb_p(delta & 0xff , PIT_CH0);	/* LSB */
>  	outb(delta >> 8 , PIT_CH0);	/* MSB */
> -	spin_unlock_irqrestore(&i8253_lock, flags);
> +	spin_unlock(&i8253_lock);
>  
>  	return 0;
>  }
> 

      reply	other threads:[~2007-10-28 16:54 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-28 23:11 Ralf Baechle
2007-10-28 16:54 ` Thomas Gleixner [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.LFD.0.9999.0710281753000.3186@localhost.localdomain \
    --to=tglx@linutronix.de \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ralf@linux-mips.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®