* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (74 commits)
fix do_sys_open() prototype
sysfs: trivial: fix sysfs_create_file kerneldoc spelling mistake
Documentation: Fix typo in SubmitChecklist.
Typo: depricated -> deprecated
Add missing profile=kvm option to Documentation/kernel-parameters.txt
fix typo about TBI in e1000 comment
proc.txt: Add /proc/stat field
small documentation fixes
Fix compiler warning in smount example program from sharedsubtree.txt
docs/sysfs: add missing word to sysfs attribute explanation
documentation/ext3: grammar fixes
Documentation/java.txt: typo and grammar fixes
Documentation/filesystems/vfs.txt: typo fix
include/asm-*/system.h: remove unused set_rmb(), set_wmb() macros
trivial copy_data_pages() tidy up
Fix typo in arch/x86/kernel/tsc_32.c
file link fix for Pegasus USB net driver help
remove unused return within void return function
Typo fixes retrun -> return
x86 hpet.h: remove broken links
...
Whilst looking up what profile=sleep did, I noticed that we missed
adding docs for the most recent addition to the profiler.
Signed-off-by: Dave Jones <davej@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
* ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-x86: (33 commits)
x86: convert cpuinfo_x86 array to a per_cpu array
x86: introduce frame_pointer() and stack_pointer()
x86 & generic: change to __builtin_prefetch()
i386: do not BUG_ON() when MSR is unknown
x86: acpi use cpu_physical_id
x86: convert cpu_llc_id to be a per cpu variable
x86: convert cpu_to_apicid to be a per cpu variable
i386: introduce "used_vectors" bitmap which can be used to reserve vectors.
x86: use raw locks during oopses
x86: honor _PAGE_PSE bit on page walks
i386: do cpuid_device_create() in CPU_UP_PREPARE instead of CPU_ONLINE.
x86: implement missing x86_64 function smp_call_function_mask()
x86: use descriptor's functions instead of inline assembly
i386: consolidate show_regs and show_registers for i386
i386: make callgraph use dump_trace() on i386/x86_64
x86: enable iommu_merge by default
i386: i386 add AMD64 Barcelona PMU MSR definitions to msr.h
x86: Unify i386 and x86-64 early quirks
x86: enable HPET on ICH3 and ICH4
x86: force enable HPET on VT8235/8237 chipsets
...
Manually fix trivial conflict with task pid container helper changes in
arch/x86/kernel/process_32.c
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
given the following:
$ grep -rw sg_def_reserved_size *
Documentation/kernel-parameters.txt: sg_def_reserved_size= [SCSI]
$
that kernel parameter looks exceedingly dead.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
>From commit cd8c93a4e04dce8f00d1ef3a476aac8bd65ae40b:
"Similar functionality was turned on by acpi_fake_ecdt=1 command line
before. Now it is on all the time."
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Since the OSS-related "sb" kernel parameter doesn't seem to be
supported, drop its reference from the kernel-parameters.txt file.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
This adds the documentation for the extended crashkernel syntax into
Documentation/kdump/kdump.txt.
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
add force_hpet boot option.
(this will be useful to make the forced-enable quirks depend on.)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, there's a CONFIG_DISABLE_CONSOLE_SUSPEND that allows one to stop
the serial console from being suspended when the rest of the machine goes
to sleep. This is incredibly useful for debugging power management-related
things; however, having it as a compile-time option has proved to be
incredibly inconvenient for us (OLPC). There are plenty of times that we
want serial console to not suspend, but for the most part we'd like serial
console to be suspended.
This drops CONFIG_DISABLE_CONSOLE_SUSPEND, and replaces it with a kernel
boot parameter (no_console_suspend). By default, the serial console will
be suspended along with the rest of the system; by passing
'no_console_suspend' to the kernel during boot, serial console will remain
alive during suspend.
For now, this is pretty serial console specific; further fixes could be
applied to make this work for things like netconsole.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the = into the __setup line.
Document the option in kernel-parameters.txt by adding a pointer
to the x86-64 specific documentation.
[ tglx: arch/x86 adaptation ]
Pointed out by Robert Day
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Convert LSM into a static interface, as the ability to unload a security
module is not required by in-tree users and potentially complicates the
overall security architecture.
Needlessly exported LSM symbols have been unexported, to help reduce API
abuse.
Parameters for the capability and root_plug modules are now specified
at boot.
The SECURITY_FRAMEWORK_VERSION macro has also been removed.
In a nutshell, there is no safe way to unload an LSM. The modular interface
is thus unecessary and broken infrastructure. It is used only by out-of-tree
modules, which are often binary-only, illegal, abusive of the API and
dangerous, e.g. silently re-vectoring SELinux.
[akpm@linux-foundation.org: cleanups]
[akpm@linux-foundation.org: USB Kconfig fix]
[randy.dunlap@oracle.com: fix LSM kernel-doc]
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Acked-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the "ramdisk" kernel parameter has been officially deprecated
since at least 2.6.18, might as well finally get rid of it.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add logo.nologo kernel boot option to disable the logo in order to provide
more screen space for kernel messages; especially useful when debugging and
screen space is more critical.
newport_con driver changes are untested.
[akpm@linux-foundation.org: cleanups, coding-style fixes]
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Optionally add a boot delay after each kernel printk() call, crudely
measured in milliseconds, with a maximum delay of 10 seconds per printk.
Enable CONFIG_BOOT_PRINTK_DELAY=y and then add (e.g.):
"lpj=loops_per_jiffy boot_delay=100"
to the kernel command line.
It has been useful in cases like "during boot, my machine just reboots or the
screen goes black" by slowing down printk, (and adding initcall_debug), we can
usually see the last thing that happened before the lights went out which is
usually a valuable clue.
[akpm@linux-foundation.org: not all architectures implement CONFIG_HZ]
[akpm@linux-foundation.org: fix lots of stuff]
[bunk@stusta.de: kernel/printk.c: make 2 variables static]
[heiko.carstens@de.ibm.com: fix slow down printk on boot compile error]
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (40 commits)
Input: use full RCU API
Input: remove tsdev interface
Input: add support for Blackfin BF54x Keypad controller
Input: appletouch - another fix for idle reset logic
HWMON: hdaps - switch to using input-polldev
Input: add support for SEGA Dreamcast keyboard
Input: omap-keyboard - don't pretend we support changing keymap
Input: lifebook - fix X and Y axis range
Input: usbtouchscreen - add support for GeneralTouch devices
Input: fix open count handling in input interfaces
Input: keyboard - add CapsShift lock
Input: adbhid - produce all CapsLock key events
Input: ALPS - add signature for ThinkPad R61
Input: jornada720_kbd - send MSC_SCAN events
Input: add support for the HP Jornada 7xx (710/720/728) touchscreen
Input: add support for HP Jornada 7xx onboard keyboard
Input: add support for HP Jornada onboard keyboard (HP6XX)
Input: ucb1400_ts - use schedule_timeout_uninterruptible
Input: xpad - fix dependancy on LEDS class
Input: auto-select INPUT for MAC_EMUMOUSEBTN option
...
Resolved conflicts manually in drivers/hwmon/applesmc.c: converting from
a class device to a device and converting to use input-polldev created a
few apparently trivial clashes..
* git://git.linux-nfs.org/pub/linux/nfs-2.6: (131 commits)
NFSv4: Fix a typo in nfs_inode_reclaim_delegation
NFS: Add a boot parameter to disable 64 bit inode numbers
NFS: nfs_refresh_inode should clear cache_validity flags on success
NFS: Fix a connectathon regression in NFSv3 and NFSv4
NFS: Use nfs_refresh_inode() in ops that aren't expected to change the inode
SUNRPC: Don't call xprt_release in call refresh
SUNRPC: Don't call xprt_release() if call_allocate fails
SUNRPC: Fix buggy UDP transmission
[23/37] Clean up duplicate includes in
[2.6 patch] net/sunrpc/rpcb_clnt.c: make struct rpcb_program static
SUNRPC: Use correct type in buffer length calculations
SUNRPC: Fix default hostname created in rpc_create()
nfs: add server port to rpc_pipe info file
NFS: Get rid of some obsolete macros
NFS: Simplify filehandle revalidation
NFS: Ensure that nfs_link() returns a hashed dentry
NFS: Be strict about dentry revalidation when doing exclusive create
NFS: Don't zap the readdir caches upon error
NFS: Remove the redundant nfs_reval_fsid()
NFSv3: Always use directory post-op attributes in nfs3_proc_lookup
...
Fix up trivial conflict due to sock_owned_by_user() cleanup manually in
net/sunrpc/xprtsock.c
* 'upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: (119 commits)
[libata] struct pci_dev related cleanups
libata: use ata_exec_internal() for PMP register access
libata: implement ATA_PFLAG_RESETTING
libata: add @timeout to ata_exec_internal[_sg]()
ahci: fix notification handling
ahci: clean up PORT_IRQ_BAD_PMP enabling
ahci: kill leftover from enabling NCQ over PMP
libata: wrap schedule_timeout_uninterruptible() in loop
libata: skip suppress reporting if ATA_EHI_QUIET
libata: clear ehi description after initial host report
pata_jmicron: match vendor and class code only
libata: add ST9160821AS / 3.ALD to NCQ blacklist
pata_acpi: ACPI driver support
libata-core: Expose gtm methods for driver use
libata: add HDT722516DLA380 to NCQ blacklist
libata: blacklist NCQ on Seagate Barracuda ST380817AS
[libata] Turn on ACPI by default
libata_scsi: Fix ATAPI transfer lengths
libata: correct handling of SRST reset sequences
libata: Integrate ACPI-based PATA/SATA hotplug - version 5
...
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6: (37 commits)
PCI: merge almost all of pci_32.h and pci_64.h together
PCI: X86: Introduce and enable PCI domain support
PCI: Add 'nodomains' boot option, and pci_domains_supported global
PCI: modify PCI bridge control ISA flag for clarity
PCI: use _CRS for PCI resource allocation
PCI: avoid P2P prefetch window for expansion ROMs
PCI: skip ISA ioresource alignment on some systems
PCI: remove transparent bridge sizing
pci: write file size to inode on proc bus file write
pci: use size stored in proc_dir_entry for proc bus files
pci: implement "pci=noaer"
PCI: fix IDE legacy mode resources
MSI: Use correct data offset for 32-bit MSI in read_msi_msg()
PCI: Fix incorrect argument order to list_add_tail() in PCI dynamic ID code
PCI: i386: Compaq EVO N800c needs PCI bus renumbering
PCI: Remove no longer correct documentation regarding MSI vector assignment
PCI: re-enable onboard sound on "MSI K8T Neo2-FIR"
PCI: quirk_vt82c586_acpi: Omit reading PCI revision ID
PCI: quirk amd_8131_mmrbc: Omit reading pci revision ID
cpqphp: Use PCI_CLASS_REVISION instead of PCI_REVISION_ID for read
...
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (75 commits)
PM: merge device power-management source files
sysfs: add copyrights
kobject: update the copyrights
kset: add some kerneldoc to help describe what these strange things are
Driver core: rename ktype_edd and ktype_efivar
Driver core: rename ktype_driver
Driver core: rename ktype_device
Driver core: rename ktype_class
driver core: remove subsystem_init()
sysfs: move sysfs file poll implementation to sysfs_open_dirent
sysfs: implement sysfs_open_dirent
sysfs: move sysfs_dirent->s_children into sysfs_dirent->s_dir
sysfs: make sysfs_root a regular directory dirent
sysfs: open code sysfs_attach_dentry()
sysfs: make s_elem an anonymous union
sysfs: make bin attr open get active reference of parent too
sysfs: kill unnecessary NULL pointer check in sysfs_release()
sysfs: kill unnecessary sysfs_get() in open paths
sysfs: reposition sysfs_dirent->s_mode.
sysfs: kill sysfs_update_file()
...
* Introduce pci_domains_supported global, hardcoded to zero if
!CONFIG_PCI_DOMAINS.
* Introduce 'nodomains' boot option, which clears pci_domains_supported
on platforms that enable it by default (x86, x86-64, and others when
they are converted to use this).
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use _CRS for PCI resource allocation
This patch resolves an issue where incorrect PCI memory and i/o ranges
are being assigned to hotplugged PCI devices on some IBM systems. The
resource mis-allocation not only makes the PCI device unuseable but
often makes the entire system unuseable due to resulting machine checks.
The hotplug capable PCI slots on the affected systems are not located
under a standard P2P bridge but are instead located under PCI root
bridges or subtractive decode P2P bridges. For example, the IBM x3850
contains 2 hotplug capable PCI-X slots and 4 hotplug capable PCIe slots
with the PCI-X slots each located under a PCI root bridge and the PCIe
slots each located under a subtractive decode P2P bridge.
The current i386/x86_64 PCI resource allocation code does not use _CRS
returned resource information. No other resource information source is
available for slots that are not below a standard P2P bridge so
incorrect ranges are being allocated from e820 hole causing the bad
result.
This patch causes the kernel to use _CRS returned resource info. It is
roughly based on a change provided by Matthew Wilcox for the ia64 kernel
in 2005. Due to possible buggy BIOS factor and possible yet to be
discovered kernel issues the function is disabled by default and can be
enabled with pci=use_crs.
Signed-off-by: Gary Hade <gary.hade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For cases in which CONFIG_PCIEAER=y (such as distro kernels), allow users
to disable PCIE Advanced Error Reporting by using "pci=noaer" on the
kernel command line.
This can be used to work around hardware or (kernel) software problems.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for an MFGPT clock event device; this allows us to use MFGPTs as
the basis for high-resolution timers.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This adds support for Multi-Function General Purpose Timers. It detects the
available timers during southbridge init, and provides an API for allocating
and setting the timers. They're higher resolution than the standard PIT, so
the MFGPTs come in handy for quite a few things.
Note that we never clobber the timers that the BIOS might have opted to use;
we just check for unused timers.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This boot parameter will allow legacy 32-bit applications which call stat()
to continue to function even if the NFSv3/v4 server uses 64-bit inode
numbers.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since this boot-time option was removed in commit
9ab7e323af, delete the reference to it.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Since this boot-time option was removed in commit
9ab7e323af, delete the reference to it.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
In MPS mode, "nosmp" and "maxcpus=0" boot a UP kernel with IOAPIC disabled.
However, in ACPI mode, these parameters didn't completely disable
the IO APIC initialization code and boot failed.
init/main.c:
Disable the IO_APIC if "nosmp" or "maxcpus=0"
undefine disable_ioapic_setup() when it doesn't apply.
i386:
delete ioapic_setup(), it was a duplicate of parse_noapic()
delete undefinition of disable_ioapic_setup()
x86_64:
rename disable_ioapic_setup() to parse_noapic() to match i386
define disable_ioapic_setup() in header to match i386
http://bugzilla.kernel.org/show_bug.cgi?id=1641
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Some hardware will malfunction at a temperature below
the BIOS provided critical shutdown threshold.
This hook allows moving the critical trip points down
to a temperature which provokes a graceful shutdown
before the hardware malfunction.
http://bugzilla.kernel.org/show_bug.cgi?id=8884
WARNING: A trip-point override will not get noticed
until the system delivers a temperature change event,
or unless thermal zone polling is enabled.
eg. "thermal.tzp=10"
Signed-off-by: Len Brown <len.brown@intel.com>
thermal.act=-1 disables all active trip points
in all ACPI thermal zones.
thermal.act=C, where C > 0, overrides all lowest temperature
active trip points in all thermal zones to C degrees Celsius.
Raising this trip-point may allow you to keep your system silent
up to a higher temperature. However, it will not allow you to
raise the lowest temperature trip point above the next higher
trip point (if there is one). Lowering this trip point may
kick in the fan sooner.
Note that overriding this trip-point will disable any BIOS attempts
to implement hysteresis around the lowest temperature trip point.
This may result in the fan starting and stopping frequently
if temperature frequently crosses C.
WARNING: raising trip points above the manufacturer's defaults
may cause the system to run at higher temperature and shorten
its life.
Signed-off-by: Len Brown <len.brown@intel.com>
thermal.nocrt=1 disables actions on _CRT and _HOT
ACPI thermal zone trip-points. They will be marked
as <disabled> in /proc/acpi/thermal_zone/*/trip_points.
There are two cases where this option is used:
1. Debugging a hot system crossing valid trip point.
If your system fan is spinning at full speed,
be sure that the vent is not clogged with dust.
Many laptops have very fine thermal fins that are easily blocked.
Check that the processor fan-sink is properly seated,
has the proper thermal grease, and is really spinning.
Check for fan related options in BIOS SETUP.
Sometimes there is a performance vs quiet option.
Defaults are generally the most conservative.
If your fan is not spinning, yet /proc/acpi/fan/
has files in it, please file a Linux/ACPI bug.
WARNING: you risk shortening the lifetime of your
hardware if you use this parameter on a hot system.
Note that this refers to all system components,
including the disk drive.
2. Working around a cool system crossing critical
trip point due to erroneous temperature reading.
Try again with CONFIG_HWMON=n
There is known potential for conflict between the
the hwmon sub-system and the ACPI BIOS.
If this fixes it, notify lm-sensors@lm-sensors.org
and linux-acpi@vger.kernel.org
Otherwise, file a Linux/ACPI bug, or notify
just linux-acpi@vger.kernel.org.
Signed-off-by: Len Brown <len.brown@intel.com>
"thermal.psv=-1" disables passive trip points
for all ACPI thermal zones.
"thermal.psv=C", where 'C' is degrees Celsius,
overrides all existing passive trip points
for all ACPI thermal zones.
thermal.psv is checked at module load time,
and in response to trip-point change events.
Note that if the system does not deliver thermal zone
temperature change events near the new trip-point,
then it will not be noticed. To force your custom
trip point to be noticed, you may need to enable polling:
eg. thermal.tzp=3000 invokes polling every 5 minutes.
Note that once passive thermal throttling is invoked,
it has its own internal Thermal Sampling Period (_TSP),
that is unrelated to _TZP.
WARNING: disabling or raising a thermal trip point
may result in increased running temperature and
shorter hardware lifetime on some systems.
Signed-off-by: Len Brown <len.brown@intel.com>
Thermal Zone Polling frequency (_TZP) is an optional ACPI object
recommending the rate that the OS should poll the associated thermal zone.
If _TZP is 0, no polling should be used.
If _TZP is non-zero, then the platform recommends that
the OS poll the thermal zone at the specified rate.
The minimum period is 30 seconds.
The maximum period is 5 minutes.
(note _TZP and thermal.tzp units are in deci-seconds,
so _TZP = 300 corresponds to 30 seconds)
If _TZP is not present, ACPI 3.0b recommends that the
thermal zone be polled at an "OS provided default frequency".
However, common industry practice is:
1. The BIOS never specifies any _TZP
2. High volume OS's from this century never poll any thermal zones
Ie. The OS depends on the platform's ability to
provoke thermal events when necessary, and
the "OS provided default frequency" is "never":-)
There is a proposal that ACPI 4.0 be updated to reflect
common industry practice -- ie. no _TZP, no polling.
The Linux kernel already follows this practice --
thermal zones are not polled unless _TZP is present and non-zero.
But thermal zone polling is useful as a workaround for systems
which have ACPI thermal control, but have an issue preventing
thermal events. Indeed, some Linux distributions still
set a non-zero thermal polling frequency for this reason.
But rather than ask the user to write a polling frequency
into all the /proc/acpi/thermal_zone/*/polling_frequency
files, here we simply document and expose the already
existing module parameter to do the same at system level,
to simplify debugging those broken platforms.
Note that thermal.tzp is a module-load time parameter only.
Signed-off-by: Len Brown <len.brown@intel.com>
"thermal.off=1" disables all ACPI thermal support at boot time.
CONFIG_ACPI_THERMAL=n can do this at build time.
"# rmmod thermal" can do this at run time,
as long as thermal is built as a module.
WARNING: On some systems, disabling ACPI thermal support
will cause the system to run hotter and reduce the
lifetime of the hardware.
Signed-off-by: Len Brown <len.brown@intel.com>