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From: Keith Owens <kaos@ocs.com.au>
To: Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao 
	<fernando@oss.ntt.co.jp>
cc: "Eric W. Biederman" <ebiederm@xmission.com>, horms@verge.net.au,
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       vgoyal@in.ibm.com, mbligh@google.com, akpm@linux-foundation.org
Subject: Re: [PATCH 1/10] safe_apic_wait_icr_idle - i386 
In-reply-to: Your message of "Wed, 25 Apr 2007 20:13:28 +0900."
             <1177499608.17974.9.camel@sebastian.intellilink.co.jp> 
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Date: Wed, 25 Apr 2007 22:55:01 +1000
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Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao (on Wed, 25 Apr 2007 20:13:28 +0900) wrote:
>+static __inline__ unsigned long safe_apic_wait_icr_idle(void)
>+{
>+	unsigned long send_status;
>+	int timeout;
>+
>+	timeout = 0;
>+	do {
>+		udelay(100);
>+		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
>+	} while (send_status && (timeout++ < 1000));
>+
>+	return send_status;
>+}
>+

safe_apic_wait_icr_idle() as coded guarantees a minimum 100 usec delay
before sending the IPI, this extra delay is unnecessary.  Change it to

	do {
		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
		if (send_status)
			break;
		udelay(100);
	} while (timeout++ < 1000);