Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262450AbVAUSif (ORCPT ); Fri, 21 Jan 2005 13:38:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262451AbVAUSif (ORCPT ); Fri, 21 Jan 2005 13:38:35 -0500 Received: from ylpvm15-ext.prodigy.net ([207.115.57.46]:15503 "EHLO ylpvm15.prodigy.net") by vger.kernel.org with ESMTP id S262450AbVAUSic (ORCPT ); Fri, 21 Jan 2005 13:38:32 -0500 Date: Fri, 21 Jan 2005 10:38:09 -0800 From: Tony Lindgren To: Zwane Mwaikambo Cc: Pavel Machek , George Anzinger , john stultz , Andrea Arcangeli , Con Kolivas , Martin Schwidefsky , linux-kernel@vger.kernel.org Subject: Re: [PATCH] dynamic tick patch Message-ID: <20050121183808.GI14554@atomide.com> References: <20050119000556.GB14749@atomide.com> <20050121174831.GE14554@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1619 Lines: 46 * Zwane Mwaikambo [050121 10:27]: > On Fri, 21 Jan 2005, Tony Lindgren wrote: > > > > This doesn't seem to cover the local APIC timer, what do you do about the > > > 1kHz tick which it's programmed to do? > > > > Sorry for the delay in replaying. Thanks for pointing that out, I > > don't know yet what to do with the local APIC timer. Have to look at > > more. > > Pavel does your test system have a Local APIC? If so that may also explain > why you didn't see a difference. Yeah, that could explain why sleep mode seems to wake up too early. > Tony, something like the following for oneshot should work, untested of > course. Perhaps you could use that for the wakeup interrupt instead? > > void setup_oneshot_apic_timer(unsigned int count) > { > unsigned int lvtt, tmp_value; > unsigned long flags; > > count *= calibration_result; > local_irq_save(flags); > lvtt = ~APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR; > apic_write_around(APIC_LVTT, lvtt); > tmp_value = apic_read(APIC_TDCR); > apic_write_around(APIC_TDCR, (tmp_value > & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) > | APIC_TDR_DIV_16); > > apic_write_around(APIC_TMICT, count/APIC_DIVISOR); > local_irq_restore(flags); > } > Thanks, I'll try it out! As George also pointed out, we should use apic timer if available. Else we can fall back on use PIT. Tony - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/