From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757566AbYILT62 (ORCPT ); Fri, 12 Sep 2008 15:58:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752780AbYILT6U (ORCPT ); Fri, 12 Sep 2008 15:58:20 -0400 Received: from mail-gx0-f16.google.com ([209.85.217.16]:64723 "EHLO mail-gx0-f16.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754764AbYILT6T (ORCPT ); Fri, 12 Sep 2008 15:58:19 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=XzJQJZPilqdsfTKSX06ztdAtIUyhATiCqNbOrNezSu3G5zYAa0zCE8afr/uBYbuk5v hg5V+dTPU5fvdVcpjVWtbDV257vEA05WsrH/QiyqO+BHIzUOeXonVKse3dHUiFMU2s0U rVVPP/P4OdAvNxK95o3OB84RxIRSEHBxVaFQ8= Date: Fri, 12 Sep 2008 23:58:24 +0400 From: Cyrill Gorcunov To: Ingo Molnar , "Maciej W. Rozycki" Cc: LKML , Yinghai Lu , Thomas Gleixner , "H. Peter Anvin" Subject: [PATCH] x86: apic - fix unused vars warning in calibrate_APIC_clock Message-ID: <20080912195824.GA8410@lenovo> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If we don't have CONFIG_X86_PM_TIMER=y compiler warns about unused variables. Move PM timer based calibration into a separate procedure and make the compiler happy. Signed-off-by: Cyrill Gorcunov --- Please review. Index: linux-2.6.git/arch/x86/kernel/apic.c =================================================================== --- linux-2.6.git.orig/arch/x86/kernel/apic.c 2008-09-12 22:46:40.000000000 +0400 +++ linux-2.6.git/arch/x86/kernel/apic.c 2008-09-12 23:55:49.000000000 +0400 @@ -538,14 +538,51 @@ static void __init lapic_cal_handler(str } } +static int __init calibrate_by_pmtimer(long deltapm, long *delta) +{ + const long pm_100ms = PMTMR_TICKS_PER_SEC / 10; + const long pm_thresh = pm_100ms / 100; + unsigned long mult; + u64 res; + +#ifndef CONFIG_X86_PM_TIMER + return -1; +#endif + + apic_printk(APIC_VERBOSE, "... PM timer delta = %ld\n", deltapm); + + /* Check, if the PM timer is available */ + if (!deltapm) + return -1; + + mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22); + + if (deltapm > (pm_100ms - pm_thresh) && + deltapm < (pm_100ms + pm_thresh)) { + apic_printk(APIC_VERBOSE, "... PM timer result ok\n"); + } else { + res = (((u64)deltapm) * mult) >> 22; + do_div(res, 1000000); + printk(KERN_WARNING "APIC calibration not consistent " + "with PM Timer: %ldms instead of 100ms\n", + (long)res); + /* Correct the lapic counter value */ + res = (((u64)(*delta)) * pm_100ms); + do_div(res, deltapm); + printk(KERN_INFO "APIC delta adjusted to PM-Timer: " + "%lu (%ld)\n", (unsigned long)res, *delta); + *delta = (long)res; + } + + return 0; +} + static int __init calibrate_APIC_clock(void) { struct clock_event_device *levt = &__get_cpu_var(lapic_events); - const long pm_100ms = PMTMR_TICKS_PER_SEC/10; - const long pm_thresh = pm_100ms/100; void (*real_handler)(struct clock_event_device *dev); unsigned long deltaj; - long delta, deltapm; + long delta; int pm_referenced = 0; local_irq_disable(); @@ -575,36 +612,9 @@ static int __init calibrate_APIC_clock(v delta = lapic_cal_t1 - lapic_cal_t2; apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta); -#ifdef CONFIG_X86_PM_TIMER - /* Check, if the PM timer is available */ - deltapm = lapic_cal_pm2 - lapic_cal_pm1; - apic_printk(APIC_VERBOSE, "... PM timer delta = %ld\n", deltapm); - - if (deltapm) { - unsigned long mult; - u64 res; - - mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22); - - if (deltapm > (pm_100ms - pm_thresh) && - deltapm < (pm_100ms + pm_thresh)) { - apic_printk(APIC_VERBOSE, "... PM timer result ok\n"); - } else { - res = (((u64) deltapm) * mult) >> 22; - do_div(res, 1000000); - printk(KERN_WARNING "APIC calibration not consistent " - "with PM Timer: %ldms instead of 100ms\n", - (long)res); - /* Correct the lapic counter value */ - res = (((u64) delta) * pm_100ms); - do_div(res, deltapm); - printk(KERN_INFO "APIC delta adjusted to PM-Timer: " - "%lu (%ld)\n", (unsigned long) res, delta); - delta = (long) res; - } - pm_referenced = 1; - } -#endif + /* we trust the PM based calibration if possible */ + pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1, + &delta); /* Calculate the scaled math multiplication factor */ lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS, @@ -646,7 +656,10 @@ static int __init calibrate_APIC_clock(v levt->features &= ~CLOCK_EVT_FEAT_DUMMY; - /* We trust the pm timer based calibration */ + /* + * PM timer calibration failed or not turned on + * so lets try APIC timer based calibration + */ if (!pm_referenced) { apic_printk(APIC_VERBOSE, "... verify APIC timer\n");