memory_failure_queue() is called when recoverable memory errors are
notified by firmware to do the recovery work.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
memory_failure() is the entry point for HWPoison memory error
recovery. It must be called in process context. But commonly
hardware memory errors are notified via MCE or NMI, so some delayed
execution mechanism must be used. In MCE handler, a work queue + ring
buffer mechanism is used.
In addition to MCE, now APEI (ACPI Platform Error Interface) GHES
(Generic Hardware Error Source) can be used to report memory errors
too. To add support to APEI GHES memory recovery, a mechanism similar
to that of MCE is implemented. memory_failure_queue() is the new
entry point that can be called in IRQ context. The next step is to
make MCE handler uses this interface too.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
printk is used by GHES to report hardware errors. Ratelimit is
enforced on the printk to avoid too many hardware error reports in
kernel log. Because there may be thousands or even millions of
corrected hardware errors during system running.
Currently, a simple scheme is used. That is, the total number of
hardware error reporting is ratelimited. This may cause some issues
in practice.
For example, there are two kinds of hardware errors occurred in
system. One is corrected memory error, because the fault memory
address is accessed frequently, there may be hundreds error report
per-second. The other is corrected PCIe AER error, it will be
reported once per-second. Because they share one ratelimit control
structure, it is highly possible that only memory error is reported.
To avoid the above issue, an error record content based throttle
algorithm is implemented in the patch. Where after the first
successful reporting, all error records that are same are throttled for
some time, to let other kinds of error records have the opportunity to
be reported.
In above example, the memory errors will be throttled for some time,
after being printked. Then the PCIe AER error will be printked
successfully.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Some APEI GHES recoverable errors are reported via NMI, but printk is
not safe in NMI context.
To solve the issue, a lock-less memory allocator is used to allocate
memory in NMI handler, save the error record into the allocated
memory, put the error record into a lock-less list. On the other
hand, an irq_work is used to delay the operation from NMI context to
IRQ context. The irq_work IRQ handler will remove nodes from
lock-less list, printk the error record and do some further processing
include recovery operation, then free the memory.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This version of the gen_pool memory allocator supports lockless
operation.
This makes it safe to use in NMI handlers and other special
unblockable contexts that could otherwise deadlock on locks. This is
implemented by using atomic operations and retries on any conflicts.
The disadvantage is that there may be livelocks in extreme cases. For
better scalability, one gen_pool allocator can be used for each CPU.
The lockless operation only works if there is enough memory available.
If new memory is added to the pool a lock has to be still taken. So
any user relying on locklessness has to ensure that sufficient memory
is preallocated.
The basic atomic operation of this allocator is cmpxchg on long. On
architectures that don't have NMI-safe cmpxchg implementation, the
allocator can NOT be used in NMI handler. So code uses the allocator
in NMI handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Cmpxchg is used to implement adding new entry to the list, deleting
all entries from the list, deleting first entry of the list and some
other operations.
Because this is a single list, so the tail can not be accessed in O(1).
If there are multiple producers and multiple consumers, llist_add can
be used in producers and llist_del_all can be used in consumers. They
can work simultaneously without lock. But llist_del_first can not be
used here. Because llist_del_first depends on list->first->next does
not changed if list->first is not changed during its operation, but
llist_del_first, llist_add, llist_add (or llist_del_all, llist_add,
llist_add) sequence in another consumer may violate that.
If there are multiple producers and one consumer, llist_add can be
used in producers and llist_del_all or llist_del_first can be used in
the consumer.
This can be summarized as follow:
| add | del_first | del_all
add | - | - | -
del_first | | L | L
del_all | | | -
Where "-" stands for no lock is needed, while "L" stands for lock is
needed.
The list entries deleted via llist_del_all can be traversed with
traversing function such as llist_for_each etc. But the list entries
can not be traversed safely before deleted from the list. The order
of deleted entries is from the newest to the oldest added one. If you
want to traverse from the oldest to the newest, you must reverse the
order by yourself before traversing.
The basic atomic operation of this list is cmpxchg on long. On
architectures that don't have NMI-safe cmpxchg implementation, the
list can NOT be used in NMI handler. So code uses the list in NMI
handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
cmpxchg() is widely used by lockless code, including NMI-safe lockless
code. But on some architectures, the cmpxchg() implementation is not
NMI-safe, on these architectures the lockless code may need a
spin_trylock_irqsave() based implementation.
This patch adds a Kconfig option: ARCH_HAVE_NMI_SAFE_CMPXCHG, so that
NMI-safe lockless code can depend on it or provide different
implementation according to it.
On many architectures, cmpxchg is only NMI-safe for several specific
operand sizes. So, ARCH_HAVE_NMI_SAFE_CMPXCHG define in this patch
only guarantees cmpxchg is NMI-safe for sizeof(unsigned long).
Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Richard Henderson <rth@twiddle.net>
CC: Mikael Starvik <starvik@axis.com>
Acked-by: David Howells <dhowells@redhat.com>
CC: Yoshinori Sato <ysato@users.sourceforge.jp>
CC: Tony Luck <tony.luck@intel.com>
CC: Hirokazu Takata <takata@linux-m32r.org>
CC: Geert Uytterhoeven <geert@linux-m68k.org>
CC: Michal Simek <monstr@monstr.eu>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
CC: Kyle McMartin <kyle@mcmartin.ca>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Chen Liqin <liqin.chen@sunplusct.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ingo Molnar <mingo@redhat.com>
CC: Chris Zankel <chris@zankel.net>
Signed-off-by: Len Brown <len.brown@intel.com>
APEI firmware first mode must be turned on explicitly on some
machines, otherwise there may be no GHES hardware error record for
hardware error notification. APEI bit in generic _OSC call can be
used to do that, but on some machine, a special WHEA _OSC call must be
used. This patch adds the support to that WHEA _OSC call.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
In APEI firmware first mode, hardware error is reported by hardware to
firmware firstly, then firmware reports the error to Linux in a GHES
error record via POLL/SCI/IRQ/NMI etc.
This may result in some issues if OS has no full APEI support. So
some firmware implementation will work in a back-compatible mode by
default. Where firmware will only notify OS in old-fashion, without
GHES record. For example, for a fatal hardware error, only NMI is
signaled, no GHES record.
To gain full APEI power on these machines, APEI bit in generic _OSC
call can be specified to tell firmware that Linux has full APEI
support. This patch adds the APEI bit support in generic _OSC call.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Some machine may have broken firmware so that GHES and firmware first
mode should be disabled. This patch adds support to that.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
GHES (Generic Hardware Error Source) is used to process hardware error
notification in firmware first mode. But because firmware first mode
can be turned on but can not be turned off, it is unreasonable to
unload the GHES module with firmware first mode turned on. To avoid
confusion, this patch makes GHES can be enabled/disabled in
configuration time, but not built as module and unloaded at run time.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch changes APEI EINJ and ERST to use apei_exec_run for
mandatory actions, and apei_exec_run_optional for optional actions.
Cc: Thomas Renninger <trenn@novell.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Some actions in APEI ERST and EINJ tables are optional, for example,
ACPI_EINJ_BEGIN_OPERATION action is used to do some preparation for
error injection, and firmware may choose to do nothing here. While
some other actions are mandatory, for example, firmware must provide
ACPI_EINJ_GET_ERROR_TYPE implementation.
Original implementation treats all actions as optional (that is, can
have no instructions), that may cause issue if firmware does not
provide some mandatory actions. To fix this, this patch adds
apei_exec_run_optional, which should be used for optional actions.
The original apei_exec_run should be used for mandatory actions.
Cc: Thomas Renninger <trenn@novell.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
printk is used by GHES to report hardware errors. Normally, the
printk will be ratelimited to avoid too many hardware error reports in
kernel log. Because there may be thousands or even millions of
corrected hardware errors during system running.
That is different for fatal hardware error, because system will go
panic as soon as possible, there will be no more than several error
records. And these error records are valuable for system fault
diagnosis, so they should not be ratelimited.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
When we debug ERST table with erst-dbg, if the error record in ERST
table is too long(>4K), it can't be read out. So this patch increases
the buffer size to 16K to ensure such error records can be read from
ERST table.
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
erst_dbg module can not work when ERST is disabled. So disable module
loading to provide clearer information to user.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The firmware on some machine will report duplicated hardware error
source ID in HEST. This is considered a firmware bug. To provide
better warning message, this patch adds duplicated hardware error
source ID detecting and corresponding printk.
This patch fixes#37412 on kernel bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=37412
Reported-by: marconifabio@ubuntu-it.org
Signed-off-by: Huang Ying <ying.huang@intel.com>
Tested-by: Mathias <janedo.spam@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/mm: Fix memory_block_size_bytes() for non-pseries
mm: Move definition of MIN_MEMORY_BLOCK_SIZE to a header
* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6:
drm/i915/ringbuffer: Idling requires waiting for the ring to be empty
Revert "drm/i915: enable rc6 by default"
drm/i915: Clean up i915_driver_load failure path
drm/i915: Enable GPU reset on Ivybridge.
drm/i915/dp: manage sink power state if possible
drm/i915/dp: consolidate AUX retry code
drm/i915/dp: remove DPMS mode tracking from DP
drm/i915/dp: try to read receiver capabilities 3 times when detecting
drm/i915/dp: read more receiver capability bits on hotplug
drm/i915/dp: use DP DPCD defines when looking at DPCD values
drm/i915/dp: retry link status read 3 times on failure
...which is measured by the size and not the amount of space remaining.
Waiting upon size-8, did one of two things. In the common case with more
than 8 bytes available to write into the ring, it would return
immediately. Otherwise, it would timeout given the impossible condition
of waiting for more space than is available in the ring, leading to
warnings such as:
[drm:intel_cleanup_ring_buffer] *ERROR* failed to quiesce render ring
whilst cleaning up: -16
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
This reverts commit a51f7a66fb.
We still have a few Ironlake and Sandybridge machines which fail when
RC6 is enabled. Better luck next release?
Signed-off-by: Keith Packard <keithp@keithp.com>
i915_driver_load adds a write-combining MTRR region for the GTT
aperture to improve memory speeds through the aperture. If
i915_driver_load fails after this, it would not have cleaned up the
MTRR. This shouldn't cause any problems, except for consuming an MTRR
register. Still, it's best to clean up completely in the failure path,
which is easily done by calling mtrr_del if the mtrr was successfully
allocated.
i915_driver_load calls i915_gem_load which register
i915_gem_inactive_shrink. If i915_driver_load fails after calling
i915_gem_load, the shrinker will be left registered. When called, it
will access freed memory and crash. The fix is to unregister the shrinker in the
failure path using code duplicated from i915_driver_unload.
i915_driver_load also has some incorrect gotos in the error cleanup
paths:
* After failing to initialize the GTT (which cannot happen, btw,
intel_gtt_get returns a fixed (non-NULL) value), it tries to
free the uninitialized WC IO mapping. Fixed this by changing the
target from out_iomapfree to out_rmmap
Signed-off-by: Keith Packard <keithp@keithp.com>
Tested-by: Lin Ming <ming.m.lin@intel.com>
Just compiling pseries in the kernel causes it to override
memory_block_size_bytes() regardless of what is the runtime
platform.
This cleans up the implementation of that function, fixing
a bug or two while at it, so that it's harmless (and potentially
useful) for other platforms. Without this, bugs in that code
would trigger a WARN_ON() in drivers/base/memory.c when
booting some different platforms.
If/when we have another platform supporting memory hotplug we
might want to either move that out to a generic place or
make it a ppc_md. callback.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The macro MIN_MEMORY_BLOCK_SIZE is currently defined twice in two .c
files, and I need it in a third one to fix a powerpc bug, so let's
first move it into a header
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
That file harkens back to the days of the big 2.4 -> 2.6 version jump,
and was based even then on older versions. Some of it is just obsolete,
and Jesper Juhl points out that it talks about kernel versions 2.6 and
should be updated to 3.0.
Remove some obsolete text, and re-phrase some other to not be 2.6-specific.
Reported-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6:
[media] msp3400: fill in v4l2_tuner based on vt->type field
[media] tuner-core.c: don't change type field in g_tuner or g_frequency
[media] cx18/ivtv: fix g_tuner support
[media] tuner-core: power up tuner when called with s_power(1)
[media] v4l2-ioctl.c: check for valid tuner type in S_HW_FREQ_SEEK
[media] tuner-core: simplify the standard fixup
[media] tuner-core/v4l2-subdev: document that the type field has to be filled in
[media] v4l2-subdev.h: remove unused s_mode tuner op
[media] feature-removal-schedule: change in how radio device nodes are handled
[media] bttv: fix s_tuner for radio
[media] pvrusb2: fix g/s_tuner support
[media] v4l2-ioctl.c: prefill tuner type for g_frequency and g/s_tuner
[media] tuner-core: fix tuner_resume: use t->mode instead of t->type
[media] tuner-core: fix s_std and s_tuner
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: drop spinlock before calling cifs_put_tlink
cifs: fix expand_dfs_referral
cifs: move bdi_setup_and_register outside of CONFIG_CIFS_DFS_UPCALL
cifs: factor smb_vol allocation out of cifs_setup_volume_info
cifs: have cifs_cleanup_volume_info not take a double pointer
cifs: fix build_unc_path_to_root to account for a prefixpath
cifs: remove bogus call to cifs_cleanup_volume_info
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86:
hp-wmi: fix use after free
dell-laptop - using buffer without mutex_lock
Revert: "dell-laptop: Toggle the unsupported hardware killswitch"
platform-drivers-x86: set backlight type to BACKLIGHT_PLATFORM
thinkpad-acpi: handle HKEY 0x4010, 0x4011 events
drivers/platform/x86: Fix memory leak
thinkpad-acpi: handle some new HKEY 0x60xx events
acer-wmi: fix bitwise bug when set device state
acer-wmi: Only update rfkill status for associated hotkey events
Since we removed sti()/cli() and related, how about removing it from
Documentation/spinlocks.txt?
Signed-off-by: Muthukumar R <muthur@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ 191.310008] WARNING: kmemcheck: Caught 32-bit read from freed memory (f0d25f14)
[ 191.310011] c056d2f088000000105fd2f00000000050415353040000000000000000000000
[ 191.310020] i i i i f f f f f f f f f f f f f f f f f f f f f f f f f f f f
[ 191.310027] ^
[ 191.310029]
[ 191.310032] Pid: 737, comm: modprobe Not tainted 3.0.0-rc5+ #268 Hewlett-Packard HP Compaq 6005 Pro SFF PC/3047h
[ 191.310036] EIP: 0060:[<f80b3104>] EFLAGS: 00010286 CPU: 0
[ 191.310039] EIP is at hp_wmi_perform_query+0x104/0x150 [hp_wmi]
[ 191.310041] EAX: f0d25601 EBX: f0d25f00 ECX: 000121cf EDX: 000121ce
[ 191.310043] ESI: f0d25f10 EDI: f0f97ea8 EBP: f0f97ec4 ESP: c173f34c
[ 191.310045] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[ 191.310046] CR0: 8005003b CR2: f540c000 CR3: 30f30000 CR4: 000006d0
[ 191.310048] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 191.310050] DR6: ffff4ff0 DR7: 00000400
[ 191.310051] [<f80b317b>] hp_wmi_dock_state+0x2b/0x40 [hp_wmi]
[ 191.310054] [<f80b6093>] hp_wmi_init+0x93/0x1a8 [hp_wmi]
[ 191.310057] [<c10011f0>] do_one_initcall+0x30/0x170
[ 191.310061] [<c107ab9f>] sys_init_module+0xef/0x1a60
[ 191.310064] [<c149f998>] sysenter_do_call+0x12/0x28
[ 191.310067] [<ffffffff>] 0xffffffff
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
This reverts commit a3d77411e8,
as it causes a mess in the wireless rfkill status on some models.
It is probably a bad idea to toggle the rfkill for all dell models
without the respect to the claim that it is hardware-controlled.
Cc: stable@kernel.org
Signed-off-by: Keng-Yu Lin <kengyu@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Patch 2e711c04db
(PM: Remove sysdev suspend, resume and shutdown operations)
deleted sysdev_suspend(), which was being relied on to call
check_wakeup_irqs() in suspend. If check_wakeup_irqs() is not
called, wake interrupts that are pending when suspend is
entered may be lost. It also breaks IRQCHIP_MASK_ON_SUSPEND,
which is handled in check_wakeup_irqs().
This patch adds a call to check_wakeup_irqs() in syscore_suspend(),
similar to what was deleted in sysdev_suspend().
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In commit f0fba2ad (ASoC: multi-component - ASoC Multi-Component
Support), the name of the ak4104 codec driver was changed without
amending the platform code which uses it as well.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
The display requires some milliseconds between GPIO_TFT_VA_EN
and GPIO_DISPLAY_ENABLE. Reorder initialisation to comply with
the display spec.
Also tune timings for better compliance with the spec.
Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
Acked-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
The backlight control is going to change back to PWM in the
upcoming Raumfeld Controller hardware revision.
Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
Acked-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
The PXA platform code has a static inline helper called
gpio_to_chip which clashes with the gpiolib namespace if we
try to expose the function with the same name from gpiolib,
and it's still confusing even if we don't do that. So rename
it to gpio_to_pxachip().
Reported-by: H Hartley Sweeten <hartleys@visionengravers.com>
Cc: Eric Miao <eric.miao@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
I came across a memory leak during a cyclic cpu-online-offline test.
Signed-off-by: Yu Luming <luming.yu@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging:
hwmon: (pmbus) Improve auto-detection of temperature status register
hwmon: (lm95241) Fix negative temperature results
hwmon: (lm95241) Fix chip detection code
It is possible that a PMBus device supports the READ_TEMPERATURE2 and/or
READ_TEMPERATURE3 registers but does not support READ_TEMPERATURE1.
Improve temperature status register detection to address this condition.
Reported-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org # 2.6.39+
Negative temperatures were returned in degrees C instead of milli-Degrees C.
Also, negative temperatures were reported for remote temperature sensors even
if the chip was configured for positive-only results.
Fix by detecting temperature modes, and by treating negative temperatures
similar to positive temperatures, with appropriate sign extension.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org # 2.6.30+
