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From: Ingo Molnar <mingo@elte.hu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [git pull] timer fixes
Date: Mon, 25 Aug 2008 19:52:26 +0200	[thread overview]
Message-ID: <20080825175226.GA9892@elte.hu> (raw)

Linus,

Please pull the latest timers-fixes-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git timers-fixes-for-linus

Thanks,

	Ingo

------------------>
Ingo Molnar (1):
      rtc: fix deadlock


 include/asm-generic/rtc.h |   12 ++++--------
 1 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/include/asm-generic/rtc.h b/include/asm-generic/rtc.h
index be4af00..71ef3f0 100644
--- a/include/asm-generic/rtc.h
+++ b/include/asm-generic/rtc.h
@@ -15,6 +15,7 @@
 #include <linux/mc146818rtc.h>
 #include <linux/rtc.h>
 #include <linux/bcd.h>
+#include <linux/delay.h>
 
 #define RTC_PIE 0x40		/* periodic interrupt enable */
 #define RTC_AIE 0x20		/* alarm interrupt enable */
@@ -43,7 +44,6 @@ static inline unsigned char rtc_is_updating(void)
 
 static inline unsigned int get_rtc_time(struct rtc_time *time)
 {
-	unsigned long uip_watchdog = jiffies;
 	unsigned char ctrl;
 	unsigned long flags;
 
@@ -53,19 +53,15 @@ static inline unsigned int get_rtc_time(struct rtc_time *time)
 
 	/*
 	 * read RTC once any update in progress is done. The update
-	 * can take just over 2ms. We wait 10 to 20ms. There is no need to
+	 * can take just over 2ms. We wait 20ms. There is no need to
 	 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
 	 * If you need to know *exactly* when a second has started, enable
 	 * periodic update complete interrupts, (via ioctl) and then 
 	 * immediately read /dev/rtc which will block until you get the IRQ.
 	 * Once the read clears, read the RTC time (again via ioctl). Easy.
 	 */
-
-	if (rtc_is_updating() != 0)
-		while (jiffies - uip_watchdog < 2*HZ/100) {
-			barrier();
-			cpu_relax();
-		}
+	if (rtc_is_updating())
+		mdelay(20);
 
 	/*
 	 * Only the values that we read from the RTC are set. We leave

             reply	other threads:[~2008-08-25 17:52 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-25 17:52 Ingo Molnar [this message]
  -- strict thread matches above, loose matches on Subject: below --
2024-04-14  8:42 [GIT PULL] timer fixes Ingo Molnar
2024-04-14 18:48 ` pr-tracker-bot
2024-04-07  8:03 Ingo Molnar
2024-04-07 16:44 ` pr-tracker-bot
2023-01-12 14:44 Ingo Molnar
2023-01-12 23:01 ` pr-tracker-bot
2022-08-13 10:25 Ingo Molnar
2022-08-13 16:25 ` Borislav Petkov
2022-08-13 20:27   ` Linus Torvalds
2022-08-14  8:57     ` Ingo Molnar
2022-08-14 12:41     ` Borislav Petkov
2022-08-14 17:24       ` Paul E. McKenney
2022-08-14 17:42         ` Borislav Petkov
2022-08-13 21:48 ` pr-tracker-bot
2020-12-27  9:26 Ingo Molnar
2020-12-27 17:27 ` pr-tracker-bot
2019-12-17 11:55 Ingo Molnar
2019-12-17 19:14 ` Linus Torvalds
2019-12-17 19:30   ` Peter Zijlstra
2019-12-17 20:16     ` Linus Torvalds
2019-12-17 20:35       ` Peter Zijlstra
2019-12-17 20:43         ` Linus Torvalds
2019-12-17 20:54           ` Peter Zijlstra
2019-12-17 19:20 ` pr-tracker-bot
2019-05-16 16:09 Ingo Molnar
2019-05-16 18:20 ` pr-tracker-bot
2019-04-20  7:45 Ingo Molnar
2019-04-20 19:25 ` pr-tracker-bot
2018-07-13 20:01 Ingo Molnar
2017-03-07 20:36 Ingo Molnar
2016-10-28  8:38 Ingo Molnar
2016-08-18 20:46 Ingo Molnar
2016-08-12 19:43 Ingo Molnar
2016-01-14 10:12 Ingo Molnar
2015-10-03 10:20 Ingo Molnar
2015-09-17  8:13 Ingo Molnar
2015-03-28 13:50 Ingo Molnar
2015-03-17 16:50 Ingo Molnar
2015-03-01 17:06 Ingo Molnar
2013-12-17 13:52 Ingo Molnar
2013-09-28 18:19 Ingo Molnar
2013-08-19  9:41 Ingo Molnar
2013-02-26 11:32 Ingo Molnar
2012-09-21 19:12 Ingo Molnar
2012-08-03 16:47 Ingo Molnar
2011-12-20 19:25 Ingo Molnar
2011-12-05 19:00 Ingo Molnar
2011-06-19  8:51 Ingo Molnar
2011-06-13  9:55 Ingo Molnar
2011-06-06 19:10 [GIT pull] " Thomas Gleixner
2011-05-20 17:52 Thomas Gleixner
2011-04-19 16:03 [GIT PULL] " Ingo Molnar
2011-04-16 10:09 Ingo Molnar
2011-04-07 17:42 Ingo Molnar
2011-02-06 12:06 Ingo Molnar
2011-01-24 13:24 Ingo Molnar
2010-11-26 13:40 Ingo Molnar
2010-03-26 15:34 Ingo Molnar
2009-12-18 18:49 Ingo Molnar
2009-10-08 18:35 Ingo Molnar
2009-08-25 18:04 Ingo Molnar
2009-06-26 19:03 Ingo Molnar
2009-04-09 15:43 Ingo Molnar
2009-01-30 23:07 [git pull] " Ingo Molnar
2009-01-26 17:21 Ingo Molnar
2009-01-06 16:18 Ingo Molnar
2008-12-04 20:52 Ingo Molnar
2008-11-11 18:47 Ingo Molnar
2008-09-23 19:41 Ingo Molnar
2008-09-17  9:59 Ingo Molnar
2008-08-22 12:24 Ingo Molnar
2008-07-24 15:18 Ingo Molnar

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