From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964831Ab1LPTwS (ORCPT ); Fri, 16 Dec 2011 14:52:18 -0500 Received: from cantor2.suse.de ([195.135.220.15]:45129 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932843Ab1LPTu5 (ORCPT ); Fri, 16 Dec 2011 14:50:57 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Dec 16 11:45:59 2011 Message-Id: <20111216194559.540097947@clark.kroah.org> User-Agent: quilt/0.50-24.1 Date: Fri, 16 Dec 2011 11:45:31 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Mark Langsdorf , Andreas Herrmann , Thomas Gleixner Subject: [34/53] x86, hpet: Immediately disable HPET timer 1 if rtc irq is masked In-Reply-To: <20111216194613.GA18395@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Langsdorf commit 2ded6e6a94c98ea453a156748cb7fabaf39a76b9 upstream. When HPET is operating in RTC mode, the TN_ENABLE bit on timer1 controls whether the HPET or the RTC delivers interrupts to irq8. When the system goes into suspend, the RTC driver sends a signal to the HPET driver so that the HPET releases control of irq8, allowing the RTC to wake the system from suspend. The switchover is accomplished by a write to the HPET configuration registers which currently only occurs while servicing the HPET interrupt. On some systems, I have seen the system suspend before an HPET interrupt occurs, preventing the write to the HPET configuration register and leaving the HPET in control of the irq8. As the HPET is not active during suspend, it does not generate a wake signal and RTC alarms do not work. This patch forces the HPET driver to immediately transfer control of the irq8 channel to the RTC instead of waiting until the next interrupt event. Signed-off-by: Mark Langsdorf Link: http://lkml.kernel.org/r/20111118153306.GB16319@alberich.amd.com Tested-by: Andreas Herrmann Signed-off-by: Andreas Herrmann Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/hpet.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -1048,6 +1048,14 @@ int hpet_rtc_timer_init(void) } EXPORT_SYMBOL_GPL(hpet_rtc_timer_init); +static void hpet_disable_rtc_channel(void) +{ + unsigned long cfg; + cfg = hpet_readl(HPET_T1_CFG); + cfg &= ~HPET_TN_ENABLE; + hpet_writel(cfg, HPET_T1_CFG); +} + /* * The functions below are called from rtc driver. * Return 0 if HPET is not being used. @@ -1059,6 +1067,9 @@ int hpet_mask_rtc_irq_bit(unsigned long return 0; hpet_rtc_flags &= ~bit_mask; + if (unlikely(!hpet_rtc_flags)) + hpet_disable_rtc_channel(); + return 1; } EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit); @@ -1124,15 +1135,11 @@ EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq); static void hpet_rtc_timer_reinit(void) { - unsigned int cfg, delta; + unsigned int delta; int lost_ints = -1; - if (unlikely(!hpet_rtc_flags)) { - cfg = hpet_readl(HPET_T1_CFG); - cfg &= ~HPET_TN_ENABLE; - hpet_writel(cfg, HPET_T1_CFG); - return; - } + if (unlikely(!hpet_rtc_flags)) + hpet_disable_rtc_channel(); if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit) delta = hpet_default_delta;