From 53cc2820acbdbcc768675bfaff321f3a8680a317 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 22 Jul 2011 09:12:50 +0000 Subject: rtc: Handle errors correctly in rtc_irq_set_state() In rtc_irq_set_state, the code checks the correctness of the parameters, but then goes on to unconditionally arms/disarms the hrtimer. Thus a random task might arm/disarm rtc timer and surprise the real owner by either generating events or by stopping them. Cc: stable@kernel.org Signed-off-by: Thomas Gleixner Signed-off-by: John Stultz --- drivers/rtc/interface.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/rtc') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index df68618f6dbb..b6bf57f25cc9 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -656,6 +656,8 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled err = -EBUSY; if (rtc->irq_task != task) err = -EACCES; + if (err) + goto out; if (enabled) { ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); @@ -664,6 +666,7 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled hrtimer_cancel(&rtc->pie_timer); } rtc->pie_enabled = enabled; +out: spin_unlock_irqrestore(&rtc->irq_task_lock, flags); return err; -- cgit From 3c8bb90efb6e3105206e4aaa9127395feeda5492 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 22 Jul 2011 09:12:51 +0000 Subject: rtc: Fix hrtimer deadlock Ben reported a lockup related to rtc. The lockup happens due to: CPU0 CPU1 rtc_irq_set_state() __run_hrtimer() spin_lock_irqsave(&rtc->irq_task_lock) rtc_handle_legacy_irq(); spin_lock(&rtc->irq_task_lock); hrtimer_cancel() while (callback_running); So the running callback never finishes as it's blocked on rtc->irq_task_lock. Use hrtimer_try_to_cancel() instead and drop rtc->irq_task_lock while waiting for the callback. Fix this for both rtc_irq_set_state() and rtc_irq_set_freq(). Cc: stable@kernel.org Reported-by: Ben Greear Signed-off-by: Thomas Gleixner Signed-off-by: John Stultz --- drivers/rtc/interface.c | 56 ++++++++++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 19 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index b6bf57f25cc9..a1ba2caa8308 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -636,6 +636,29 @@ void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) } EXPORT_SYMBOL_GPL(rtc_irq_unregister); +static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) +{ + /* + * We always cancel the timer here first, because otherwise + * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); + * when we manage to start the timer before the callback + * returns HRTIMER_RESTART. + * + * We cannot use hrtimer_cancel() here as a running callback + * could be blocked on rtc->irq_task_lock and hrtimer_cancel() + * would spin forever. + */ + if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0) + return -1; + + if (enabled) { + ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq); + + hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); + } + return 0; +} + /** * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs * @rtc: the rtc device @@ -651,24 +674,21 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled int err = 0; unsigned long flags; +retry: spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task != NULL && task == NULL) err = -EBUSY; if (rtc->irq_task != task) err = -EACCES; - if (err) - goto out; - - if (enabled) { - ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); - hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); - } else { - hrtimer_cancel(&rtc->pie_timer); + if (!err) { + if (rtc_update_hrtimer(rtc, enabled) < 0) { + spin_unlock_irqrestore(&rtc->irq_task_lock, flags); + cpu_relax(); + goto retry; + } + rtc->pie_enabled = enabled; } - rtc->pie_enabled = enabled; -out: spin_unlock_irqrestore(&rtc->irq_task_lock, flags); - return err; } EXPORT_SYMBOL_GPL(rtc_irq_set_state); @@ -690,20 +710,18 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) if (freq <= 0) return -EINVAL; - +retry: spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task != NULL && task == NULL) err = -EBUSY; if (rtc->irq_task != task) err = -EACCES; - if (err == 0) { + if (!err) { rtc->irq_freq = freq; - if (rtc->pie_enabled) { - ktime_t period; - hrtimer_cancel(&rtc->pie_timer); - period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); - hrtimer_start(&rtc->pie_timer, period, - HRTIMER_MODE_REL); + if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) { + spin_unlock_irqrestore(&rtc->irq_task_lock, flags); + cpu_relax(); + goto retry; } } spin_unlock_irqrestore(&rtc->irq_task_lock, flags); -- cgit From 6e7a333eaa522ef73be01caec7a01521490aaf00 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 22 Jul 2011 09:12:51 +0000 Subject: rtc: Limit RTC PIE frequency The RTC pie hrtimer is self rearming. We really need to limit the frequency to something sensible. Thus limit it to the 8192Hz max value from the rtc man documentation Cc: Willy Tarreau Cc: stable@kernel.org Signed-off-by: Thomas Gleixner [jstultz: slightly reworked to use RTC_MAX_FREQ value] Signed-off-by: John Stultz --- drivers/rtc/interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index a1ba2caa8308..44e91e598f8d 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -708,7 +708,7 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) int err = 0; unsigned long flags; - if (freq <= 0) + if (freq <= 0 || freq > RTC_MAX_FREQ) return -EINVAL; retry: spin_lock_irqsave(&rtc->irq_task_lock, flags); -- cgit From bf6ed027bcc93f8d54d321fe87f0434b25699eb1 Mon Sep 17 00:00:00 2001 From: Axel Lin Date: Wed, 10 Aug 2011 21:11:26 +0800 Subject: rtc: ep93xx: Fix 'rtc' may be used uninitialized warning commit 92d921c5d "rtc: ep93xx: Initialize drvdata before registering device" ensures the drvdata is initialized prior to registering the rtc device. But it set the drvdata to an uninitialized pointer. Thus calling platform_get_drvdata in ep93xx_rtc_remove does not get correct address. This patch fixes below warning by adding struct rtc_device *rtc to struct ep93xx_rtc. Then set platform drvdata to ep93xx_rtc instead of rtc. CC drivers/rtc/rtc-ep93xx.o drivers/rtc/rtc-ep93xx.c: In function 'ep93xx_rtc_probe': drivers/rtc/rtc-ep93xx.c:154: warning: 'rtc' may be used uninitialized in this function Signed-off-by: Axel Lin Signed-off-by: John Stultz --- drivers/rtc/rtc-ep93xx.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-ep93xx.c b/drivers/rtc/rtc-ep93xx.c index 335551d333b2..14a42a1edc66 100644 --- a/drivers/rtc/rtc-ep93xx.c +++ b/drivers/rtc/rtc-ep93xx.c @@ -36,6 +36,7 @@ */ struct ep93xx_rtc { void __iomem *mmio_base; + struct rtc_device *rtc; }; static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, @@ -130,7 +131,6 @@ static int __init ep93xx_rtc_probe(struct platform_device *pdev) { struct ep93xx_rtc *ep93xx_rtc; struct resource *res; - struct rtc_device *rtc; int err; ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL); @@ -151,12 +151,12 @@ static int __init ep93xx_rtc_probe(struct platform_device *pdev) return -ENXIO; pdev->dev.platform_data = ep93xx_rtc; - platform_set_drvdata(pdev, rtc); + platform_set_drvdata(pdev, ep93xx_rtc); - rtc = rtc_device_register(pdev->name, + ep93xx_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, &ep93xx_rtc_ops, THIS_MODULE); - if (IS_ERR(rtc)) { - err = PTR_ERR(rtc); + if (IS_ERR(ep93xx_rtc->rtc)) { + err = PTR_ERR(ep93xx_rtc->rtc); goto exit; } @@ -167,7 +167,7 @@ static int __init ep93xx_rtc_probe(struct platform_device *pdev) return 0; fail: - rtc_device_unregister(rtc); + rtc_device_unregister(ep93xx_rtc->rtc); exit: platform_set_drvdata(pdev, NULL); pdev->dev.platform_data = NULL; @@ -176,11 +176,11 @@ exit: static int __exit ep93xx_rtc_remove(struct platform_device *pdev) { - struct rtc_device *rtc = platform_get_drvdata(pdev); + struct ep93xx_rtc *ep93xx_rtc = platform_get_drvdata(pdev); sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files); platform_set_drvdata(pdev, NULL); - rtc_device_unregister(rtc); + rtc_device_unregister(ep93xx_rtc->rtc); pdev->dev.platform_data = NULL; return 0; -- cgit From dec35d19c4ec65b94df3b27b6e373f0d48c9cd32 Mon Sep 17 00:00:00 2001 From: Ilkka Koskinen Date: Wed, 16 Mar 2011 06:07:14 +0000 Subject: rtc: rtc-twl: Switch to using threaded irq The driver is accessing to i2c bus in interrupt handler. Therefore, it should use threaded irq. Signed-off-by: Ilkka Koskinen Acked-by: Balaji T K Signed-off-by: John Stultz --- drivers/rtc/rtc-twl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c index 9a81f778d6b2..1963cddbf214 100644 --- a/drivers/rtc/rtc-twl.c +++ b/drivers/rtc/rtc-twl.c @@ -462,7 +462,7 @@ static int __devinit twl_rtc_probe(struct platform_device *pdev) if (ret < 0) goto out1; - ret = request_irq(irq, twl_rtc_interrupt, + ret = request_threaded_irq(irq, NULL, twl_rtc_interrupt, IRQF_TRIGGER_RISING, dev_name(&rtc->dev), rtc); if (ret < 0) { -- cgit From 34d623d11316cb69f9e8cc5eb50d3792b5c302b6 Mon Sep 17 00:00:00 2001 From: Sebastian Reichel Date: Tue, 31 May 2011 08:51:39 +0000 Subject: rtc: rtc-twl: Remove lockdep related local_irq_enable() Now that the irq is properly threaded (due to it needing i2c access) we should also remove the local_irq_enable() call in twl_rtc_interrupt. Testing this with Pandaboard, the RTC is still working. [Reworked commit message -jstultz] Signed-off-by: John Stultz --- drivers/rtc/rtc-twl.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c index 1963cddbf214..9677bbc433f9 100644 --- a/drivers/rtc/rtc-twl.c +++ b/drivers/rtc/rtc-twl.c @@ -362,14 +362,6 @@ static irqreturn_t twl_rtc_interrupt(int irq, void *rtc) int res; u8 rd_reg; -#ifdef CONFIG_LOCKDEP - /* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which - * we don't want and can't tolerate. Although it might be - * friendlier not to borrow this thread context... - */ - local_irq_enable(); -#endif - res = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG); if (res) goto out; -- cgit From 938f97bcf1bdd1b681d5d14d1d7117a2e22d4434 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Fri, 22 Jul 2011 09:12:51 +0000 Subject: rtc: Fix RTC PIE frequency limit Thomas earlier submitted a fix to limit the RTC PIE freq, but picked 5000Hz out of the air. Willy noticed that we should instead use the 8192Hz max from the rtc man documentation. Cc: Willy Tarreau Cc: stable@kernel.org Cc: Thomas Gleixner Signed-off-by: John Stultz --- drivers/rtc/interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 3195dbd3ec34..eb4c88316a15 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -708,7 +708,7 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) int err = 0; unsigned long flags; - if (freq <= 0 || freq > 5000) + if (freq <= 0 || freq > RTC_MAX_FREQ) return -EINVAL; retry: spin_lock_irqsave(&rtc->irq_task_lock, flags); -- cgit From 4e8896cde182b4eab6f2d0af9b6eef87720fae0d Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Thu, 25 Aug 2011 15:59:22 -0700 Subject: drivers/rtc/rtc-s3c.c: correct debug messages RTC-S3C used to print out debug messages incorrectly. This patch corrects incorrect outputs. (undecoded bcd numbers, incorrectly decoded register values) This patch affects the pr-debug messages only. Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Acked-by: Kukjin Kim Cc: Alessandro Zummo Cc: Changhwan Youn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-s3c.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c index 9329dbb9ebab..067207afc086 100644 --- a/drivers/rtc/rtc-s3c.c +++ b/drivers/rtc/rtc-s3c.c @@ -152,10 +152,6 @@ static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) goto retry_get_time; } - pr_debug("read time %04d.%02d.%02d %02d:%02d:%02d\n", - 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday, - rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec); - rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec); rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min); rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour); @@ -164,6 +160,11 @@ static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year); rtc_tm->tm_year += 100; + + pr_debug("read time %04d.%02d.%02d %02d:%02d:%02d\n", + 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday, + rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec); + rtc_tm->tm_mon -= 1; clk_disable(rtc_clk); @@ -269,10 +270,9 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) clk_enable(rtc_clk); pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n", alrm->enabled, - 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, + 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec); - alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN; writeb(0x00, base + S3C2410_RTCALM); -- cgit From 62d1760180c84cba68cc83696fa0bde0593007bd Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Thu, 25 Aug 2011 15:59:24 -0700 Subject: drivers/rtc/rtc-s3c.c: allow multiple open / allow no-ioctl-open'ed rtc to have irq. The previous rtc-s3c had two issues related with its IRQ. 1. Users cannot open rtc multiple times because an open operation calls request_irq on the same IRQ. (e.g., two user processes wants to open and read RTC time from rtc-s3c at the same time) 2. If alarm is set and no one has the rtc opened with filesystem (either the alarm is set by kernel/boot-loader or user set an alarm and closed rtc dev file), the pending bit is not cleared and no further interrupt is invoked. When the alarm is used by the system itself such as a resume from suspend-to-RAM or other Low-power modes/idle, this is a critical issue. This patch mitigates these issues by calling request_irq at probe and free_irq at remove. Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Acked-by: Kukjin Kim Cc: Alessandro Zummo Cc: Changhwan Youn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-s3c.c | 67 +++++++++++++++++++-------------------------------- 1 file changed, 25 insertions(+), 42 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c index 067207afc086..4e7c04e773e0 100644 --- a/drivers/rtc/rtc-s3c.c +++ b/drivers/rtc/rtc-s3c.c @@ -319,49 +319,7 @@ static int s3c_rtc_proc(struct device *dev, struct seq_file *seq) return 0; } -static int s3c_rtc_open(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct rtc_device *rtc_dev = platform_get_drvdata(pdev); - int ret; - - ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq, - IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev); - - if (ret) { - dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret); - return ret; - } - - ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq, - IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev); - - if (ret) { - dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret); - goto tick_err; - } - - return ret; - - tick_err: - free_irq(s3c_rtc_alarmno, rtc_dev); - return ret; -} - -static void s3c_rtc_release(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct rtc_device *rtc_dev = platform_get_drvdata(pdev); - - /* do not clear AIE here, it may be needed for wake */ - - free_irq(s3c_rtc_alarmno, rtc_dev); - free_irq(s3c_rtc_tickno, rtc_dev); -} - static const struct rtc_class_ops s3c_rtcops = { - .open = s3c_rtc_open, - .release = s3c_rtc_release, .read_time = s3c_rtc_gettime, .set_time = s3c_rtc_settime, .read_alarm = s3c_rtc_getalarm, @@ -425,6 +383,9 @@ static int __devexit s3c_rtc_remove(struct platform_device *dev) { struct rtc_device *rtc = platform_get_drvdata(dev); + free_irq(s3c_rtc_alarmno, rtc); + free_irq(s3c_rtc_tickno, rtc); + platform_set_drvdata(dev, NULL); rtc_device_unregister(rtc); @@ -548,10 +509,32 @@ static int __devinit s3c_rtc_probe(struct platform_device *pdev) s3c_rtc_setfreq(&pdev->dev, 1); + ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq, + IRQF_DISABLED, "s3c2410-rtc alarm", rtc); + if (ret) { + dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret); + goto err_alarm_irq; + } + + ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq, + IRQF_DISABLED, "s3c2410-rtc tick", rtc); + if (ret) { + dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret); + free_irq(s3c_rtc_alarmno, rtc); + goto err_tick_irq; + } + clk_disable(rtc_clk); return 0; + err_tick_irq: + free_irq(s3c_rtc_alarmno, rtc); + + err_alarm_irq: + platform_set_drvdata(pdev, NULL); + rtc_device_unregister(rtc); + err_nortc: s3c_rtc_enable(pdev, 0); clk_disable(rtc_clk); -- cgit From a7402deb324f62106566f5a95199a54c41e200ef Mon Sep 17 00:00:00 2001 From: Mike Waychison Date: Fri, 12 Aug 2011 21:04:30 +0000 Subject: rtc: Initialized rtc_time->tm_isdst Even though the Linux kernel does not use the tm_isdst field, it is exposed as part of the ABI. This field can accidentally be left initialized, which is why we currently memset buffers returned to userland in rtc_read_time. There is a case however where the field can return garbage from the stack though when using the RTC_ALM_READ ioctl on the rtc device. This ioctl invokes rtc_read_alarm, which is careful to memset the rtc_wkalrm buffer that is copied to userland, but it then uses a struct copy to assign to alarm->time given the return value from rtc_ktime_to_tm(). rtc_ktime_to_tm() is implemented by calling rtc_time_to_tm using a derivative seconds counds from ktime, but rtc_time_to_tm does not assign a value to ->tm_isdst. This results in garbage from rtc_ktime_to_tm()'s frame ending up being copied out to userland as part of the returned rtc_wkalrm. Fix this by initializing rtc_time->tm_isdst to 0 in rtc_time_to_tm. Signed-off-by: Mike Waychison Signed-off-by: John Stultz --- drivers/rtc/rtc-lib.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c index 075f1708deae..c4cf05731118 100644 --- a/drivers/rtc/rtc-lib.c +++ b/drivers/rtc/rtc-lib.c @@ -85,6 +85,8 @@ void rtc_time_to_tm(unsigned long time, struct rtc_time *tm) time -= tm->tm_hour * 3600; tm->tm_min = time / 60; tm->tm_sec = time - tm->tm_min * 60; + + tm->tm_isdst = 0; } EXPORT_SYMBOL(rtc_time_to_tm); -- cgit From 7e72c686347562b4a275c97b4bdd7a79c1f23c65 Mon Sep 17 00:00:00 2001 From: Todd Poynor Date: Wed, 10 Aug 2011 20:20:36 -0700 Subject: rtc: twl: Fix registration vs. init order Only register as an RTC device after the hardware has been successfully initialized. The RTC class driver will call back to this driver to read a pending alarm, and other drivers watching for new devices on the RTC class may read the RTC time upon registration. Such access might occur while the RTC is stopped, prior to clearing pending alarms, etc. The new ordering also avoids leaving the platform device drvdata set to an unregistered struct rtc_device * on probe errors. Signed-off-by: Todd Poynor Signed-off-by: John Stultz --- drivers/rtc/rtc-twl.c | 52 ++++++++++++++++++++++++--------------------------- 1 file changed, 24 insertions(+), 28 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c index 9677bbc433f9..20687d55e7a7 100644 --- a/drivers/rtc/rtc-twl.c +++ b/drivers/rtc/rtc-twl.c @@ -420,24 +420,12 @@ static struct rtc_class_ops twl_rtc_ops = { static int __devinit twl_rtc_probe(struct platform_device *pdev) { struct rtc_device *rtc; - int ret = 0; + int ret = -EINVAL; int irq = platform_get_irq(pdev, 0); u8 rd_reg; if (irq <= 0) - return -EINVAL; - - rtc = rtc_device_register(pdev->name, - &pdev->dev, &twl_rtc_ops, THIS_MODULE); - if (IS_ERR(rtc)) { - ret = PTR_ERR(rtc); - dev_err(&pdev->dev, "can't register RTC device, err %ld\n", - PTR_ERR(rtc)); - goto out0; - - } - - platform_set_drvdata(pdev, rtc); + goto out1; ret = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG); if (ret < 0) @@ -454,14 +442,6 @@ static int __devinit twl_rtc_probe(struct platform_device *pdev) if (ret < 0) goto out1; - ret = request_threaded_irq(irq, NULL, twl_rtc_interrupt, - IRQF_TRIGGER_RISING, - dev_name(&rtc->dev), rtc); - if (ret < 0) { - dev_err(&pdev->dev, "IRQ is not free.\n"); - goto out1; - } - if (twl_class_is_6030()) { twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK, REG_INT_MSK_LINE_A); @@ -472,28 +452,44 @@ static int __devinit twl_rtc_probe(struct platform_device *pdev) /* Check RTC module status, Enable if it is off */ ret = twl_rtc_read_u8(&rd_reg, REG_RTC_CTRL_REG); if (ret < 0) - goto out2; + goto out1; if (!(rd_reg & BIT_RTC_CTRL_REG_STOP_RTC_M)) { dev_info(&pdev->dev, "Enabling TWL-RTC.\n"); rd_reg = BIT_RTC_CTRL_REG_STOP_RTC_M; ret = twl_rtc_write_u8(rd_reg, REG_RTC_CTRL_REG); if (ret < 0) - goto out2; + goto out1; } /* init cached IRQ enable bits */ ret = twl_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG); if (ret < 0) + goto out1; + + rtc = rtc_device_register(pdev->name, + &pdev->dev, &twl_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) { + ret = PTR_ERR(rtc); + dev_err(&pdev->dev, "can't register RTC device, err %ld\n", + PTR_ERR(rtc)); + goto out1; + } + + ret = request_threaded_irq(irq, NULL, twl_rtc_interrupt, + IRQF_TRIGGER_RISING, + dev_name(&rtc->dev), rtc); + if (ret < 0) { + dev_err(&pdev->dev, "IRQ is not free.\n"); goto out2; + } - return ret; + platform_set_drvdata(pdev, rtc); + return 0; out2: - free_irq(irq, rtc); -out1: rtc_device_unregister(rtc); -out0: +out1: return ret; } -- cgit