From 0f74964627e0ece4ac8da0e2cd01906ec322b4fe Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 12 Jul 2006 09:03:10 -0700 Subject: [PATCH] [PATCH] lockdep: HPET/RTC fix Joseph Fannin reported that hpet_rtc_interrupt() enables hardirqs in irq context: [ 25.628000] [] trace_hardirqs_on+0xce/0x200 [ 25.628000] [] _spin_unlock_irq+0x31/0x70 [ 25.628000] [] rtc_get_rtc_time+0x44/0x1a0 [ 25.628000] [] hpet_rtc_interrupt+0x21b/0x280 [ 25.628000] [] handle_IRQ_event+0x31/0x70 [ 25.628000] [] handle_edge_irq+0xe7/0x210 [ 25.628000] [] do_IRQ+0x92/0x120 [ 25.628000] [] common_interrupt+0x25/0x2c the call of rtc_get_rtc_time() is highly suspect. At a minimum we need the patch below to save/restore hardirq state. Signed-off-by: Ingo Molnar Cc: Joseph Fannin Cc: John Stultz Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/rtc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c index 6ccc364c08df..6e6a7c7a7eff 100644 --- a/drivers/char/rtc.c +++ b/drivers/char/rtc.c @@ -1245,7 +1245,7 @@ static int rtc_proc_open(struct inode *inode, struct file *file) void rtc_get_rtc_time(struct rtc_time *rtc_tm) { - unsigned long uip_watchdog = jiffies; + unsigned long uip_watchdog = jiffies, flags; unsigned char ctrl; #ifdef CONFIG_MACH_DECSTATION unsigned int real_year; @@ -1272,7 +1272,7 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm) * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is * only updated by the RTC when initially set to a non-zero value. */ - spin_lock_irq(&rtc_lock); + spin_lock_irqsave(&rtc_lock, flags); rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS); rtc_tm->tm_min = CMOS_READ(RTC_MINUTES); rtc_tm->tm_hour = CMOS_READ(RTC_HOURS); @@ -1286,7 +1286,7 @@ void rtc_get_rtc_time(struct rtc_time *rtc_tm) real_year = CMOS_READ(RTC_DEC_YEAR); #endif ctrl = CMOS_READ(RTC_CONTROL); - spin_unlock_irq(&rtc_lock); + spin_unlock_irqrestore(&rtc_lock, flags); if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {