From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: rtc-linux@googlegroups.com MIME-Version: 1.0 Received: from mail-wm0-x244.google.com (mail-wm0-x244.google.com. [2a00:1450:400c:c09::244]) by gmr-mx.google.com with ESMTPS id r74si2640764wme.3.2016.08.31.15.59.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 31 Aug 2016 15:59:08 -0700 (PDT) Received: by mail-wm0-x244.google.com with SMTP id w207so5700151wmw.0 for ; Wed, 31 Aug 2016 15:59:08 -0700 (PDT) From: Gabriele Mazzotta To: a.zummo@towertech.it, alexandre.belloni@free-electrons.com Cc: rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org, matthew.garrett@nebula.com, Gabriele Mazzotta Subject: [rtc-linux] [PATCH v2 1/2] rtc-cmos: Ensure no expired alarm is left enabled after resume Date: Thu, 1 Sep 2016 00:58:59 +0200 Message-Id: <20160831225900.20122-1-gabriele.mzt@gmail.com> Reply-To: rtc-linux@googlegroups.com Content-Type: text/plain; charset=UTF-8 List-ID: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , Some BIOSes, such as the one of the Dell XPS13 9333, wake the system when an alarm goes off without informing the OS. If any of the RTC_IRQMASK bits is set when this happens and hpet is enabled, the alarm is not automatically cleared at resume. As consequence, the user must manually clear the alarm writing 0 to wakealarm before being able to set a new alarm. Ensure this never happens. Signed-off-by: Gabriele Mazzotta --- drivers/rtc/rtc-cmos.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 1dec52f..62d5b33 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -900,10 +900,32 @@ static inline int cmos_poweroff(struct device *dev) #ifdef CONFIG_PM_SLEEP +static bool cmos_is_wkalrm_expired(struct device *dev) +{ + struct cmos_rtc *cmos = dev_get_drvdata(dev); + struct rtc_wkalrm alarm; + struct rtc_time now; + time64_t t_now; + time64_t t_expires; + int ret; + + ret = rtc_read_alarm(cmos->rtc, &alarm); + if (ret) { + dev_err(dev, "Could not read alarm: err=%d\n", ret); + return false; + } + t_expires = rtc_tm_to_time64(&alarm.time); + cmos_read_time(dev, &now); + t_now = rtc_tm_to_time64(&now); + + return t_expires <= t_now; +} + static int cmos_resume(struct device *dev) { struct cmos_rtc *cmos = dev_get_drvdata(dev); unsigned char tmp; + bool is_wkalrm_expired; if (cmos->enabled_wake) { if (cmos->wake_off) @@ -913,6 +935,8 @@ static int cmos_resume(struct device *dev) cmos->enabled_wake = 0; } + is_wkalrm_expired = cmos_is_wkalrm_expired(dev); + spin_lock_irq(&rtc_lock); tmp = cmos->suspend_ctrl; cmos->suspend_ctrl = 0; @@ -939,6 +963,17 @@ static int cmos_resume(struct device *dev) tmp &= ~RTC_AIE; hpet_mask_rtc_irq_bit(RTC_AIE); } while (mask & RTC_AIE); + + /* + * If RTC_AIE is set and we have an alarm set to go off in the + * past, then the BIOS woke the system when the alarm went off + * and we now have to clear it. + */ + if ((tmp & RTC_AIE) && is_wkalrm_expired) { + rtc_update_irq(cmos->rtc, 1, mask); + tmp &= ~RTC_AIE; + CMOS_WRITE(tmp, RTC_CONTROL); + } } spin_unlock_irq(&rtc_lock); -- 2.9.3 -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . Please read http://groups.google.com/group/rtc-linux/web/checklist before submitting a driver. --- You received this message because you are subscribed to the Google Groups "rtc-linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to rtc-linux+unsubscribe@googlegroups.com. For more options, visit https://groups.google.com/d/optout.