Matt Fleming 47997d756a x86/rtc: Don't recursively acquire rtc_lock ... A deadlock was introduced on x86 in commit ef68c8f87e ("x86: Serialize EFI time accesses on rtc_lock") because efi_get_time() and friends can be called with rtc_lock already held by read_persistent_time(), e.g.: timekeeping_init() read_persistent_clock() <-- acquire rtc_lock efi_get_time() phys_efi_get_time() <-- acquire rtc_lock <DEADLOCK> To fix this let's push the locking down into the get_wallclock() and set_wallclock() implementations. Only the clock implementations that access the x86 RTC directly need to acquire rtc_lock, so it makes sense to push the locking down into the rtc, vrtc and efi code. The virtualization implementations don't require rtc_lock to be held because they provide their own serialization. Signed-off-by: Matt Fleming <matt.fleming@intel.com> Acked-by: Jan Beulich <jbeulich@novell.com> Acked-by: Avi Kivity <avi@redhat.com> [for the virtualization aspect] Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Josh Boyer <jwboyer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2011-09-21 16:16:09 +02:00
..
Makefile	mrst_pmu: driver for Intel Moorestown Power Management Unit	2011-08-03 19:06:12 -04:00
early_printk_mrst.c	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-01-13 10:05:56 -08:00
mrst.c	sfi: table irq 0xFF means 'no interrupt'	2011-08-26 09:03:29 -07:00
pmu.c	mrst_pmu: driver for Intel Moorestown Power Management Unit	2011-08-03 19:06:12 -04:00
pmu.h	mrst_pmu: driver for Intel Moorestown Power Management Unit	2011-08-03 19:06:12 -04:00
vrtc.c	x86/rtc: Don't recursively acquire rtc_lock	2011-09-21 16:16:09 +02:00