From f6d5b33125c4fa63c16f7f54c533338c9695d82c Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 29 Mar 2011 18:00:27 -0700 Subject: RTC: Fix early irqs caused by calling rtc_set_alarm too early When we register an rtc device at boot, we read the alarm value in hardware and set the rtc device's aie_timer to that value. The initial method to do this was to simply call rtc_set_alarm() with the value read from hardware. However, this may cause problems as rtc_set_alarm may enable interupts, and the RTC alarm might fire, which can cause invalid pointer dereferencing since the RTC registration is not complete. This patch solves the issue by initializing the rtc_device.aie_timer y hand via rtc_initialize_alarm(). This avoids any calls to the RTC hardware which might enable interrupts too early. CC: Thomas Gleixner CC: Alessandro Zummo Reported-by: Konrad Rzeszutek Wilk Tested-by: Konrad Rzeszutek Wilk Signed-off-by: John Stultz --- include/linux/rtc.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/rtc.h') diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 2ca7e8a78060..877ece45426f 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -228,6 +228,8 @@ extern int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alrm); extern int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alrm); +extern int rtc_initialize_alarm(struct rtc_device *rtc, + struct rtc_wkalrm *alrm); extern void rtc_update_irq(struct rtc_device *rtc, unsigned long num, unsigned long events); -- cgit v1.2.3-71-gd317 From 9796cc964daf7f18b4cd84c86975b3bc3804ca5a Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Thu, 26 May 2011 16:25:12 -0700 Subject: drivers/rtc/rtc-mxc.c: remove defines already included in rtc.h [akpm@linux-foundation.org: retain the code comments] Signed-off-by: Wolfram Sang Cc: Vladimir Zapolskiy Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-mxc.c | 6 ------ include/linux/rtc.h | 8 ++++---- 2 files changed, 4 insertions(+), 10 deletions(-) (limited to 'include/linux/rtc.h') diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c index d814417bee8c..39e41fbdf08b 100644 --- a/drivers/rtc/rtc-mxc.c +++ b/drivers/rtc/rtc-mxc.c @@ -55,12 +55,6 @@ static const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = { { MAX_PIE_FREQ, RTC_SAM7_BIT }, }; -/* Those are the bits from a classic RTC we want to mimic */ -#define RTC_IRQF 0x80 /* any of the following 3 is active */ -#define RTC_PF 0x40 /* Periodic interrupt */ -#define RTC_AF 0x20 /* Alarm interrupt */ -#define RTC_UF 0x10 /* Update interrupt for 1Hz RTC */ - #define MXC_RTC_TIME 0 #define MXC_RTC_ALARM 1 diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 877ece45426f..b27ebea25660 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -92,10 +92,10 @@ struct rtc_pll_info { #define RTC_PLL_SET _IOW('p', 0x12, struct rtc_pll_info) /* Set PLL correction */ /* interrupt flags */ -#define RTC_IRQF 0x80 /* any of the following is active */ -#define RTC_PF 0x40 -#define RTC_AF 0x20 -#define RTC_UF 0x10 +#define RTC_IRQF 0x80 /* Any of the following is active */ +#define RTC_PF 0x40 /* Periodic interrupt */ +#define RTC_AF 0x20 /* Alarm interrupt */ +#define RTC_UF 0x10 /* Update interrupt for 1Hz RTC */ #ifdef __KERNEL__ -- cgit v1.2.3-71-gd317