Signed-off-by: Adrian Bunk <bunk@stusta.de>

Add infrastructure to track "maximum allowable latency" for power saving
policies.

The reason for adding this infrastructure is that power management in the
idle loop needs to make a tradeoff between latency and power savings
(deeper power save modes have a longer latency to running code again).  The
code that today makes this tradeoff just does a rather simple algorithm;
however this is not good enough: There are devices and use cases where a
lower latency is required than that the higher power saving states provide.
 An example would be audio playback, but another example is the ipw2100
wireless driver that right now has a very direct and ugly acpi hook to
disable some higher power states randomly when it gets certain types of
error.

The proposed solution is to have an interface where drivers can

* announce the maximum latency (in microseconds) that they can deal with
* modify this latency
* give up their constraint

and a function where the code that decides on power saving strategy can
query the current global desired maximum.

This patch has a user of each side: on the consumer side, ACPI is patched
to use this, on the producer side the ipw2100 driver is patched.

A generic maximum latency is also registered of 2 timer ticks (more and you
lose accurate time tracking after all).

While the existing users of the patch are x86 specific, the infrastructure
is not.  I'd like to ask the arch maintainers of other architectures if the
infrastructure is generic enough for their use (assuming the architecture
has such a tradeoff as concept at all), and the sound/multimedia driver
owners to look at the driver facing API to see if this is something they
can use.

[akpm@osdl.org: cleanups]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jesse Barnes <jesse.barnes@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

In cases where the acpi memory-add event does not containe the pxm (node)
infomation allow the driver to look up node info based on the address.  The
acpi_get_node call returns -1 if it can't decode the pxm info, this causes
add_memory to panic.  acpi_get_node would have to decode the resource from the
handle (a lenghty proposition).  This seems to be the cleanist point to
interject the hook.

[kamezawa.hiroyu@jp.fujitsu.com: build fixes]
[y-goto@jp.fujitsu.com: build fixes]
Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

* Rougly half of callers already do it by not checking return value
* Code in drivers/acpi/osl.c does the following to be sure:

	(void)kmem_cache_destroy(cache);

* Those who check it printk something, however, slab_error already printed
  the name of failed cache.
* XFS BUGs on failed kmem_cache_destroy which is not the decision
  low-level filesystem driver should make. Converted to ignore.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

i2c: Constify i2c_algorithm declarations, part 2

Make struct i2c_algorithm declarations const in all i2c bus drivers
where it is possible.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

__might_sleep+0x8e/0x93
acpi_os_wait_semaphore+0x50/0xa3
acpi_ut_acquire_mutex+0x28/0x6a
acpi_ns_get_node+0x46/0x88
acpi_ns_evaluate+0x2d/0xfc
acpi_rs_set_srs_method_data+0xc5/0xe1
acpi_set_current_resources+0x31/0x3f
acpi_pci_link_set+0xfc/0x1a5
irqrouter_resume+0x48/0x5f

and

__might_sleep+0x8e/0x93
kmem_cache_alloc+0x2a/0x8f
acpi_evaluate_integer+0x32/0x96
acpi_bus_get_status+0x30/0x84
acpi_pci_link_set+0x12a/0x1a5
irqrouter_resume+0x48/0x5f

http://bugzilla.kernel.org/show_bug.cgi?id=6810

Signed-off-by: Len Brown <len.brown@intel.com>

While going through the code, I found out some memory leaks and potential
crashes in drivers/acpi/hotkey.c Please find the patch to fix them.

This patch does the following,

1. Fixes memory leaks in error paths of hotkey_write_config

2. Fixes freeing unallocated pointers in the error paths of hotkey_write_config

3. Uses a loop instead of linear searching for parsing the userspace
   input in get_params

4. Uses array of char * instead of passing 4 pointer parameters
   explicitly into the init_{poll_}hotkey_* static functions

Signed-off-by: Andrew Morton <akpm@osdl.org>
Acked-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

This is to remove noisy useless message at boot.  The message is a ton of
"ACPI Exception (acpi_memory-0492): AE_ERROR, handle is no memory device"

In my emulation, number of memory devices are not so many (only 6), but,
this messages are displayed 114 times.

It is showed by acpi_memory_register_notify_handler() which is called by
acpi_walk_namespace().

acpi_walk_namespace() parses all of ACPI's namespace and execute
acpi_memory_register_notify_handler().  So, it is called for all of the
device which is defined in namespace.  If the parsing device is not memory,
acpi_memhotplug ignores it due to "no match" and will parse next device.
This is normal route, not an exception.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>