linux-toradex.git/arch/x86/kernel/rtc.c, branch v3.1

x86/rtc: Don't recursively acquire rtc_lock

2011-09-21T14:16:09+00:00

A deadlock was introduced on x86 in commit ef68c8f87ed1 ("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 

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 
Acked-by: Jan Beulich 
Acked-by: Avi Kivity  [for the virtualization aspect]
Cc: "H. Peter Anvin" 
Cc: Zhang Rui 
Cc: Josh Boyer 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

rtc: cmos: Add OF bindings

2011-02-23T21:27:55+00:00

This allows to load the OF driver based informations from the device
tree. Systems without BIOS may need to perform some initialization.
PowerPC creates a PNP device from the OF information and performs this
kind of initialization in their private PCI quirk. This looks more
generic.

This patch also avoids registering the platform RTC driver on X86 if
we have a device tree blob. Otherwise we would setup the device based
on the hardcoded information in arch/x86 rather than the device tree
based one.

[ tglx: Changed "int of_have_populated_dt()" to bool as recommended by
        Grant ]

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Dirk Brandewie 
Acked-by: Grant Likely 
Cc: sodaville@linutronix.de
Cc: devicetree-discuss@lists.ozlabs.org
Cc: rtc-linux@googlegroups.com
Cc: Alessandro Zummo 
LKML-Reference: <1298405266-1624-12-git-send-email-bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner

set_rtc_mmss: show warning message only once

2011-01-13T16:03:07+00:00

Occasionally the system gets into a state where the CMOS clock has gotten
slightly ahead of current time and the periodic update of RTC fails.  The
message is a nuisance and repeats spamming the log.

  See: http://www.ntp.org/ntpfaq/NTP-s-trbl-spec.htm#Q-LINUX-SET-RTC-MMSS

Rather than just removing the message, make it show only once and reduce
severity since it indicates a normal and non urgent condition.

Signed-off-by: Stephen Hemminger 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Ralf Baechle 
Cc: David Howells 
Cc: Paul Mundt 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-09-18T21:05:47+00:00

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (38 commits)
  x86: Move get/set_wallclock to x86_platform_ops
  x86: platform: Fix section annotations
  x86: apic namespace cleanup
  x86: Distangle ioapic and i8259
  x86: Add Moorestown early detection
  x86: Add hardware_subarch ID for Moorestown
  x86: Add early platform detection
  x86: Move tsc_init to late_time_init
  x86: Move tsc_calibration to x86_init_ops
  x86: Replace the now identical time_32/64.c by time.c
  x86: time_32/64.c unify profile_pc
  x86: Move calibrate_cpu to tsc.c
  x86: Make timer setup and global variables the same in time_32/64.c
  x86: Remove mca bus ifdef from timer interrupt
  x86: Simplify timer_ack magic in time_32.c
  x86: Prepare unification of time_32/64.c
  x86: Remove do_timer hook
  x86: Add timer_init to x86_init_ops
  x86: Move percpu clockevents setup to x86_init_ops
  x86: Move xen_post_allocator_init into xen_pagetable_setup_done
  ...

Fix up conflicts in arch/x86/include/asm/io_apic.h

x86: Move get/set_wallclock to x86_platform_ops

2009-09-16T12:34:50+00:00

get/set_wallclock() have already a set of platform dependent
implementations (default, EFI, paravirt). MRST will add another
variant.

Moving them to platform ops simplifies the existing code and minimizes
the effort to integrate new variants.

Signed-off-by: Feng Tang 
LKML-Reference: 
Signed-off-by: Thomas Gleixner

timekeeping: Increase granularity of read_persistent_clock()

2009-08-15T08:55:46+00:00

The persistent clock of some architectures (e.g. s390) have a
better granularity than seconds. To reduce the delta between the
host clock and the guest clock in a virtualized system change the 
read_persistent_clock function to return a struct timespec.

Signed-off-by: Martin Schwidefsky 
Cc: Ingo Molnar 
Acked-by: John Stultz 
Cc: Daniel Walker 
LKML-Reference: <20090814134811.013873340@de.ibm.com>
Signed-off-by: Thomas Gleixner

x86: rtc.c cleanup

2009-03-21T11:26:37+00:00

Impact: cleanup

 - fix various style problems
  - fix header file issues

Signed-off-by: Jaswinder Singh Rajput

rtc: use bcd2bin/bin2bcd

2008-10-20T15:52:41+00:00

Change various rtc related code to use the new bcd2bin/bin2bcd functions
instead of the obsolete BCD_TO_BIN/BIN_TO_BCD/BCD2BIN/BIN2BCD macros.

Signed-off-by: Adrian Bunk 
Acked-by: Alessandro Zummo 
Cc: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86: register a platform RTC device if PNP doesn't describe it

2008-10-14T23:30:14+00:00

Most if not all x86 platforms have an RTC device, but sometimes the RTC
is not exposed as a PNP0b00/PNP0b01/PNP0b02 device in PNPBIOS or ACPI:

    http://bugzilla.kernel.org/show_bug.cgi?id=11580
    https://bugzilla.redhat.com/show_bug.cgi?id=451188

It's best if we can discover the RTC via PNP because then we know
which flavor of device it is, where it lives, and which IRQ it uses.

But if we can't, we should register a platform device using the
compiled-in RTC_PORT/RTC_IRQ resource assumptions.

Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki 
Acked-by: David Brownell 
Reported-by: Rik Theys 
Reported-by: shr_msn@yahoo.com.tw
Signed-off-by: Linus Torvalds

provide rtc_cmos platform device

2008-06-13T01:05:42+00:00

Recently (around 2.6.25) I've noticed that RTC no longer works for me.  It
turned out this is because I use pnpacpi=off kernel option to work around
the parport_pc bugs.  I always did so, but RTC used to work fine in the
past, and now it have regressed.

The patch fixes the problem by creating the platform device for the RTC
when PNP is disabled.  This may also help running the PNP-enabled kernel
on an older PCs.

Signed-off-by: Stas Sergeev 
Cc: David Brownell 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Bjorn Helgaas 
Cc: Adam Belay 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds