linux/arch
David P. Reed bbbd99955b x86: on x86_64, correct reading of PC RTC when update in progress in time_64.c
Correct potentially unstable PC RTC time register reading in time_64.c

Stop the use of an incorrect technique for reading the standard PC RTC
timer, which is documented to "disconnect" time registers from the bus
while updates are in progress.  The use of UIP flag while interrupts
are disabled to protect a 244 microsecond window is one of the
Motorola spec sheet's documented ways to read the RTC time registers
reliably.

tglx: removed locking changes from original patch, as they gain nothing
(read_persistent_clock is only called during boot, suspend, resume - so
no hot path affected) and conflict with the paravirt locking scheme
(see 32bit code), which we do not want to complicate for no benefit.

Signed-off-by: David P. Reed <dpreed@reed.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-11-17 16:27:01 +01:00
..
alpha alpha: sg_virt() fallout 2007-10-23 12:31:05 +02:00
arm Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm 2007-11-16 18:32:08 -08:00
avr32 [AVR32] Export intc_get_pending symbol 2007-11-15 13:47:20 +01:00
blackfin Blackfin arch: reclaim a few bytes from the end of our init section 2007-10-30 12:00:02 +08:00
cris CRISv10 fasttimer: Scrap INLINE and name timeval_cmp better 2007-11-14 18:45:47 -08:00
frv FRV: Remove the section annotation on free_initmem() 2007-11-09 15:02:25 -08:00
h8300 Kbuild/doc: fix links to Documentation files 2007-10-30 14:26:30 -07:00
ia64 Add IORESOUCE_BUSY flag for System RAM 2007-11-14 18:45:39 -08:00
m32r spelling fixes: arch/m32r/ 2007-10-20 01:14:39 +02:00
m68k m68k: sg fallout 2007-10-24 08:55:40 +02:00
m68knommu m68knommu: mark mem init functions as __init 2007-10-23 20:45:44 -07:00
mips [MIPS] N32 needs to use the compat version of sys_nfsservctl. 2007-11-15 23:21:52 +00:00
parisc parisc: fix sg_page() fallout 2007-10-23 09:49:31 +02:00
powerpc [POWERPC] Silence an annoying boot message 2007-11-13 16:23:47 +11:00
ppc [POWERPC] Avoid unpaired stwcx. on some processors 2007-11-13 16:22:43 +11:00
s390 sched: restore deterministic CPU accounting on powerpc 2007-11-09 22:39:38 +01:00
sh Merge branch 'page_colouring_despair' 2007-11-08 17:01:42 +09:00
sh64 sh64: Kill off duplicate includes. 2007-11-05 12:18:17 +09:00
sparc [SPARC]: Remove duplicate includes. 2007-11-06 21:23:11 -08:00
sparc64 [SPARC]: Remove duplicate includes. 2007-11-06 21:23:11 -08:00
um uml: fix build for !CONFIG_PRINTK 2007-11-14 18:45:43 -08:00
v850 spelling fixes: arch/v850/ 2007-10-20 01:24:05 +02:00
x86 x86: on x86_64, correct reading of PC RTC when update in progress in time_64.c 2007-11-17 16:27:01 +01:00
xtensa Kbuild/doc: fix links to Documentation files 2007-10-30 14:26:30 -07:00