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88b8d33b1c
linux/drivers/rtc
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Adrian Huang 88b8d33b1c rtc: cmos: Cancel alarm timer if alarm time is equal to now+1 seconds 
Steps to reproduce the problem:
	1) Enable RTC wake-up option in BIOS Setup
	2) Issue one of these commands in the OS: "poweroff"
	   or "shutdown -h now"
	3) System will shut down and then reboot automatically

Root-cause of the issue:
	1) During the shutdown process, the hwclock utility is used
	   to save the system clock to hardware clock (RTC).
	2) The hwclock utility invokes ioctl() with RTC_UIE_ON. The
	   kernel configures the RTC alarm for the periodic interrupt
	   (every 1 second).
	3) The hwclock uitlity closes the /dev/rtc0 device, and the
	   kernel disables the RTC alarm irq (AIE bit of Register B)
	   via ioctl() with RTC_UIE_OFF. But, the configured alarm
	   time is the current_time + 1.
	4) After the next 1 second is elapsed, the AF (alarm
	   interrupt flag) of Register C is set.
	5) The S5 handler in BIOS is invoked to configure alarm
	   registers (enable AIE bit and configure alarm date/time).
	   But, BIOS does not clear the previous interrupt status
	   during alarm configuration. Therefore, "AF=AIE=1" causes
	   the rtc device to trigger an interrupt.
	6) So, the machine reboots automatically right after shutdown.

This patch cancels the alarm timer if the following condictions are
met (suggested by Alexandre):
	1) The configured alarm time is equal to current_time + 1
	   seconds.
	2) The AIE timer is not in use.

The member 'alarm_expires' is introduced in struct cmos_rtc because
of the following reasons:
	1) The configured alarm time can be retrieved from
	   cmos_read_alarm(), but we need to take the 'wrapped
	   timestamp' and 'time rollover' into consideration. The
	   function __rtc_read_alarm() eliminates the concerns. To
	   avoid the duplicated code in the lower level RTC driver,
	   invoking __rtc_read_alarm from the lower level RTC driver
	   is not encouraged. Moreover, the compilation error 'the
	   undefined __rtc_read_alarm" is observed if the lower level
	   RTC driver is compiled as a kernel module.
	2) The uie_rtctimer.node.expires and aie_timer.node.expires can
	   be retrieved for the configured alarm time. But, the problem
	   is that either of them might configure the CMOS alarm time.
	   We cannot make sure UIE timer or AIE tiemr configured the
	   CMOS alarm time before. (uie_rtctimer or aie_timer is enabled
	   and then is disabled).
	3) The patch introduces the member 'alarm_expires' to keep the
	   newly configured alarm time, so the above-mentioned concerns
	   can be eliminated.

The issue goes away after 20-time shutdown tests.

Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Tested-by: Egbert Eich <eich@suse.de>
Tested-by: Diego Ercolani <diego.ercolani@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05 13:19:08 +02:00
..
class.c rtc: switch to using is_visible() to control sysfs attributes 2015-09-05 13:19:07 +02:00
hctosys.c rtc: use more standard kernel logging styles 2015-04-17 09:04:02 -04:00
interface.c rtc: interface: Remove rtc_set_mmss() 2015-06-25 01:13:43 +02:00
Kconfig rtc: da9063: Add DA9062 RTC capability to DA9063 RTC driver 2015-09-05 13:19:08 +02:00
Makefile rtc: add rtc-lpc24xx driver 2015-09-05 13:19:06 +02:00
rtc-88pm80x.c rtc: 88pm80x: add device tree support 2015-09-05 13:19:05 +02:00
rtc-88pm860x.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-ab3100.c drivers/rtc/ab3100: Update driver to address y2038/y2106 issues 2015-04-03 08:18:25 +02:00
rtc-ab8500.c rtc: ab8500: Constify platform_device_id 2015-06-19 20:03:20 +02:00
rtc-ab-b5ze-s3.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-abx80x.c rtc: add rtc-abx80x, a driver for the Abracon AB x80x i2c rtc 2015-05-05 17:10:10 -07:00
rtc-armada38x.c rtc: armada38x: Remove unused variable from armada38x_rtc_set_time() 2015-07-18 00:42:31 +02:00
rtc-as3722.c drivers/rtc/rtc-as3722.c: use SIMPLE_DEV_PM_OPS macro 2014-04-03 16:21:22 -07:00
rtc-at32ap700x.c rtc: at32ap700x: update author email 2015-06-25 01:12:50 +02:00
rtc-at91rm9200.c drivers/rtc/rtc-at91rm9200.c: make IO endian agnostic 2015-04-17 09:04:12 -04:00
rtc-at91rm9200.h
rtc-at91sam9.c rtc: at91sam9: rework wakeup and interrupt handling 2015-03-04 22:10:59 +01:00
rtc-au1xxx.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-bfin.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-bq32k.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-bq4802.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-cmos.c rtc: cmos: Cancel alarm timer if alarm time is equal to now+1 seconds 2015-09-05 13:19:08 +02:00
rtc-coh901331.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-core.h rtc: switch to using is_visible() to control sysfs attributes 2015-09-05 13:19:07 +02:00
rtc-da9052.c drivers/rtc/rtc-da9052.c: register ability of alarm to wake device from suspend 2015-04-17 09:04:00 -04:00
rtc-da9055.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-da9063.c rtc: da9063: Add DA9062 RTC capability to DA9063 RTC driver 2015-09-05 13:19:08 +02:00
rtc-davinci.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-dev.c rtc: dev: properly manage lifetime of dev and cdev in rtc device 2015-09-05 13:19:07 +02:00
rtc-digicolor.c rtc: driver for Conexant Digicolor CX92755 on-chip RTC 2015-04-17 09:04:01 -04:00
rtc-dm355evm.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-ds1216.c rtc: simplify use of devm_ioremap_resource 2015-06-25 01:13:40 +02:00
rtc-ds1286.c rtc: simplify use of devm_ioremap_resource 2015-06-25 01:13:40 +02:00
rtc-ds1302.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-ds1305.c rtc: remove use of seq_printf return value 2015-04-15 16:35:24 -07:00
rtc-ds1307.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-ds1343.c drivers/rtc/rtc-ds1343.c: add support of nvram for maxim dallas rtc ds1343 2014-08-08 15:57:19 -07:00
rtc-ds1347.c rtc: add support for maxim dallas rtc ds1347 2014-04-03 16:21:23 -07:00
rtc-ds1374.c rtc: fix drivers that consider 0 as a valid IRQ in client->irq 2015-09-05 13:19:07 +02:00
rtc-ds1390.c rtc: rtc-ds1390: remove unnecessary OOM messages 2014-04-03 16:21:17 -07:00
rtc-ds1511.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-ds1553.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-ds1672.c rtc: ds1672, max6900, max8998: Add MODULE_DEVICE_TABLE 2015-06-25 01:13:36 +02:00
rtc-ds1685.c rtc: ds1685: Use module_platform_driver 2015-09-05 13:19:05 +02:00
rtc-ds1742.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-ds2404.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-ds3232.c rtc: fix drivers that consider 0 as a valid IRQ in client->irq 2015-09-05 13:19:07 +02:00
rtc-ds3234.c drivers/rtc/rtc-ds3234.c: remove empty function 2013-07-03 16:07:56 -07:00
rtc-efi-platform.c rtc: use more standard kernel logging styles 2015-04-17 09:04:02 -04:00
rtc-efi.c rtc: efi: use correct EFI 'epoch' 2015-06-25 01:13:44 +02:00
rtc-em3027.c drivers/rtc/rtc-em3027.c: add device tree support 2015-04-17 09:03:59 -04:00
rtc-ep93xx.c rtc: ep93xx: Use readl/writel for io 2015-06-25 01:13:38 +02:00
rtc-fm3130.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-gemini.c rtc: gemini: fix cocci warnings 2015-06-25 01:13:45 +02:00
rtc-generic.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-hid-sensor-time.c rtc: hid-sensor-time: Constify platform_device_id 2015-06-19 20:03:20 +02:00
rtc-hym8563.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-imxdi.c rtc: imxdi: when locked, do not fail silently 2015-06-19 20:03:21 +02:00
rtc-isl1208.c rtc: isl1208: Replace deprecated rtc_tm_to_time() 2015-06-25 01:13:42 +02:00
rtc-isl12022.c rtc: use rtc_valid_tm() error code when reading date/time 2015-09-05 13:19:06 +02:00
rtc-isl12057.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-jz4740.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-lib.c rtc/lib: Provide y2038 safe rtc_tm_to_time()/rtc_time_to_tm() replacement 2014-11-21 12:00:00 -08:00
rtc-lp8788.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-lpc24xx.c rtc: add rtc-lpc24xx driver 2015-09-05 13:19:06 +02:00
rtc-lpc32xx.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-ls1x.c MIPS: Loongson: Naming style cleanup and rework 2015-06-21 21:53:59 +02:00
rtc-m41t80.c rtc: use more standard kernel logging styles 2015-04-17 09:04:02 -04:00
rtc-m41t93.c drivers/rtc/rtc-m41t93.c: remove empty function 2013-07-03 16:07:56 -07:00
rtc-m41t94.c drivers/rtc/rtc-m41t94.c: remove empty function 2013-07-03 16:07:57 -07:00
rtc-m48t35.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-m48t59.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-m48t86.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-max6900.c rtc: ds1672, max6900, max8998: Add MODULE_DEVICE_TABLE 2015-06-25 01:13:36 +02:00
rtc-max6902.c drivers/rtc/rtc-max6902.c: remove empty function 2013-07-03 16:07:57 -07:00
rtc-max8907.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-max8925.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-max8997.c rtc: use more standard kernel logging styles 2015-04-17 09:04:02 -04:00
rtc-max8998.c rtc: ds1672, max6900, max8998: Add MODULE_DEVICE_TABLE 2015-06-25 01:13:36 +02:00
rtc-max77686.c rtc: max77686: Report platform modalias to fix module autoload 2015-06-25 01:13:37 +02:00
rtc-max77802.c rtc: max77802: Report platform modalias to fix module autoload 2015-06-25 01:13:37 +02:00
rtc-mc13xxx.c rtc: mc13xxx: fix obfuscated and wrong format string 2015-06-25 01:13:35 +02:00
rtc-mcp795.c drivers/rtc: add support for Microchip MCP795 2014-06-06 16:08:08 -07:00
rtc-moxart.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-mpc5121.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-mrst.c rtc: remove use of seq_printf return value 2015-04-15 16:35:24 -07:00
rtc-msm6242.c rtc: use more standard kernel logging styles 2015-04-17 09:04:02 -04:00
rtc-mt6397.c rtc: mt6397: implement suspend/resume function in rtc-mt6397 driver 2015-09-05 13:19:08 +02:00
rtc-mv.c rtc: mv: correct 24 hour error message 2015-06-25 01:13:45 +02:00
rtc-mxc.c rtc: mxc: add support of device tree 2015-08-05 20:03:56 +08:00
rtc-nuc900.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-omap.c drivers/rtc/rtc-omap.c: use module_platform_driver 2015-04-17 09:04:02 -04:00
rtc-opal.c rtc: opal: Enable alarms only when opal supports tpo 2015-09-05 13:19:06 +02:00
rtc-palmas.c rtc: palmas: Initialise bb_charging flag before using it 2015-06-25 01:13:40 +02:00
rtc-pcap.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-pcf2123.c rtc: use rtc_valid_tm() error code when reading date/time 2015-09-05 13:19:06 +02:00
rtc-pcf2127.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-pcf8523.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-pcf8563.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-pcf8583.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-pcf50633.c rtc: rtc-pcf50633: use devm_*() functions 2013-04-29 18:28:38 -07:00
rtc-pcf85063.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-pl030.c drivers/rtc/rtc-pl030.c: use devm_kzalloc() instead of kmalloc() 2013-11-13 12:09:31 +09:00
rtc-pl031.c drivers/rtc/rtc-pl03x.c: remove unnecessary amba_set_drvdata() 2013-11-13 12:09:31 +09:00
rtc-pm8xxx.c Merge branch 'platform/remove_owner' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux into driver-core-next 2014-11-03 19:53:56 -08:00
rtc-proc.c
rtc-ps3.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-puv3.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-pxa.c drivers/rtc/rtc-pxa.c: make of_device_id array const 2014-06-06 16:08:09 -07:00
rtc-r9701.c rtc: rtc-r9701: use spi_set_drvdata() 2013-04-29 18:28:34 -07:00
rtc-rc5t583.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-rk808.c drivers/rtc/rtc-rk808.c: fix rtc time reading issue 2015-02-13 21:21:43 -08:00
rtc-rp5c01.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-rs5c313.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-rs5c348.c drivers/rtc/rtc-rs5c348.c: use dev_get_platdata() 2013-11-13 12:09:29 +09:00
rtc-rs5c372.c drivers/rtc/rtc-rs5c372.c: use %*ph to dump small buffers 2014-10-14 02:18:19 +02:00
rtc-rv3029c2.c drivers/rtc/rtc-rv3029c2.c: fix potential race condition 2014-04-03 16:21:24 -07:00
rtc-rx4581.c drivers/rtc/rtc-rx4581.c: remove empty function 2013-07-03 16:07:58 -07:00
rtc-rx8025.c rtc: rx8025: remove obsolete local_irq_disable() and local_irq_enable() for rtc_update_irq() 2015-09-05 13:19:07 +02:00
rtc-rx8581.c rtc: Drop owner assignment from i2c_driver 2015-09-05 13:19:06 +02:00
rtc-s3c.c rtc: s3c: Integrate Exynos3250 into S3C6410 2015-06-19 20:03:20 +02:00
rtc-s3c.h
rtc-s5m.c drivers/rtc/rtc-s5m.c: allow usage on device type different than main MFD type 2015-04-17 09:04:11 -04:00
rtc-s35390a.c rtc: rtc-s35390a: use devm_*() functions 2013-04-29 18:28:38 -07:00
rtc-sa1100.c drivers/rtc/rtc-sa1100.c: make of_device_id array const 2014-06-06 16:08:09 -07:00
rtc-sh.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-sirfsoc.c rtc: sirfsoc: move to regmap APIs from platform-specific APIs 2015-09-05 13:19:06 +02:00
rtc-snvs.c rtc: snvs: use syscon to access register 2015-07-15 10:15:10 +08:00
rtc-spear.c rtc: simplify use of devm_ioremap_resource 2015-06-25 01:13:40 +02:00
rtc-st-lpc.c rtc: st: Update IP layout information to include Clocksource 2015-07-23 17:07:35 +01:00
rtc-starfire.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-stk17ta8.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-stmp3xxx.c rtc: stmp3xxx: use optional crystal in low power states 2015-04-17 09:03:59 -04:00
rtc-sun4v.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-sun6i.c rtc: sun6i: Add sun6i RTC driver 2014-09-19 12:39:19 +02:00
rtc-sunxi.c rtc: sunxi: Replace deprecated rtc_tm_to_time() 2015-06-25 01:13:42 +02:00
rtc-sysfs.c rtc: switch to using is_visible() to control sysfs attributes 2015-09-05 13:19:07 +02:00
rtc-tegra.c rtc: remove use of seq_printf return value 2015-04-15 16:35:24 -07:00
rtc-test.c drivers/rtc/test: Update driver to address y2038/y2106 issues 2015-04-03 08:18:24 +02:00
rtc-tile.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-tps6586x.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-tps65910.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-tps80031.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-twl.c rtc: use more standard kernel logging styles 2015-04-17 09:04:02 -04:00
rtc-tx4939.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-v3020.c rtc: rtc-v3020: use gpio_request_array() 2015-06-25 01:13:38 +02:00
rtc-vr41xx.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-vt8500.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
rtc-wm831x.c drivers/rtc/rtc-wm831x.c: remove empty function 2013-07-03 16:07:59 -07:00
rtc-wm8350.c rtc: rtc-wm8350: switch to using SIMPLE_DEV_PM_OPS 2013-04-29 18:28:32 -07:00
rtc-x1205.c drivers/rtc/rtc-x1205.c: use sign_extend32() for sign extension 2015-04-17 09:03:59 -04:00
rtc-xgene.c rtc: drop owner assignment from platform_drivers 2014-10-20 16:21:31 +02:00
systohc.c rtc: NTP: Add CONFIG_RTC_SYSTOHC_DEVICE for NTP synchronization 2015-06-25 01:13:42 +02:00