It turned out that it is almost impossible to trust ACPI, BIOS & Co.
regarding the C states. This was the reason to switch the local apic
timer off in C2 state already. OTOH there are sane and well behaving
systems, which get punished by that decision.
Allow the user to confirm that the local apic timer is trustworthy in C2
state. This keeps the default behaviour on the safe side.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use IPI for blacklisted CPUs, add parameter IPI vs LAPIC
Currently, Linux disables lapic timer for all machines with C2 and higher
C-state support.
According to Intel only specific Intel models (Banias/Dothan) are broken
in respect of not waking up from C2 with lapic.
However, I am not sure about the naming of the parameter and how it
could/should get integrated into the dyntick part
(CONFIG_GENERIC_CLOCKEVENTS). There, a more fine grained check (TSC
still running?, ..) is needed? Does this make sense (always use
CLOCK_EVT_NOTIFY_BROADCAST_ON, but use OFF if forced by use_ipi=0:
clockevents_notify(use_ipi ? CLOCK_EVT_NOTIFY_BROADCAST_ON :
CLOCK_EVT_NOTIFY_BROADCAST_OFF, &pr->id);
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch allows for ibm-acpi to coexist (with diminished functionality) with
other drivers like ACPI_BAY. ibm-acpi will simply disable the functions it is
not able to register ACPI notifiers for.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Chris Wedgwood <cw@f00f.org>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Moving disable GPEs from enter_sleep up into sleep_prepare fixed
the disabled SCI on S4 on Acer laptops.
However, it caused an immediate S3 resume on the HP nx6125.
Apparently, on the HP, a GPE was getting re-enabled after
the prepare, but before the enter.
Close that window by restoring the GPE disable on enter.
This is redundant in most cases, but closes this window,
where S3 and S4 paths differ.
Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Ray Lee <ray-lk@madrabbit.org>
When a BIOS bug presents multiple APIC/MADTs,
Linux currently uses the 1st and ignores the 2nd.
But some machines work better if we use the 2nd.
http://bugzilla.kernel.org/show_bug.cgi?id=7465
Add a warning and boot parameter "acpi_apic_instance=2"
to allow parsing the 2nd.
No change to default behaviour in this patch.
Signed-off-by: Len Brown <len.brown@intel.com>
Delay the read of the EC status register until
after the event that caused it occurs -- otherwise
it is possible to read and act on stale status that was
associated with the previous event.
Do this with a perpetually incrementing "event_count" to detect
when a new event occurs and it is safe to read status.
There is no workaround for polling mode -- it is inherently
exposed to reading and acting on stale status, since it
doesn't have an interrupt to tell it the event completed.
http://bugzilla.kernel.org/show_bug.cgi?id=8110
Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Correct some of the most obvious spelling and grammar
mistakes in drivers/acpi/video.c (comments and printk output).
Signed-off-by: Julius Volz <juliusrv@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
IMHO, ACPI disabled due to DMI failure or blacklisted year should be noted,
as is done with other ACPI blacklisting.
This will help people troubleshoot when ACPI isn't working. Status quo is
a mysterious "ACPI Disabled" message without explanation on BIOS that
implements ACPI but not DMI. This is actually fairly common on embedded
x86 boards.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Andrew Morton
Len Brown
Thomas Gleixner
Linus Torvalds
Thomas Renninger
Henrique de Moraes Holschuh
Al Viro
Alexey Starikovskiy
Alexey Starikovskiy
Robert P. J. Day
Julius Volz
Anthony Godshall, Ampro Computers, Inc