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Date: Mon, 14 Jul 2008 10:04:02 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Akinobu Mita <akinobu.mita@gmail.com>
Cc: linux-kernel@vger.kernel.org, "Michael H. Warfield" <mhw@wittsend.com>,
       Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH] ip2: avoid add_timer() with pending timer
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On Mon, 14 Jul 2008 11:49:55 +0900 Akinobu Mita <akinobu.mita@gmail.com> wrote:

> @@ -746,10 +742,8 @@ ip2_loadmain(int *iop, int *irqp)
>  			}
>  			if ( ip2config.irq[i] == CIR_POLL ) {
>  retry:
> -				if (!TimerOn) {
> -					PollTimer.expires = POLL_TIMEOUT;
> -					add_timer ( &PollTimer );
> -					TimerOn = 1;
> +				if (!timer_pending(&PollTimer)) {
> +					mod_timer(&PollTimer, POLL_TIMEOUT);
>  					printk( KERN_INFO "IP2: polling\n");

This change to ip2_loadmain() might be racy if it actually did
anything.  But afaict timer_pending() can never be true here (we're
only called from module_init()) so it can and should be removed.