Commit caf5c03f (ACPI: Move acpi_bus_get_device() from bus.c to
scan.c) caused acpi_bus_get_device() to be exported using
EXPORT_SYMBOL_GPL(), but that broke some binary drivers in
existence, so revert that change.
Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch fixes the issues indicated by the test results that
ipmi_msg_handler() is invoked in atomic context.
BUG: scheduling while atomic: kipmi0/18933/0x10000100
Modules linked in: ipmi_si acpi_ipmi ...
CPU: 3 PID: 18933 Comm: kipmi0 Tainted: G AW 3.10.0-rc7+ #2
Hardware name: QCI QSSC-S4R/QSSC-S4R, BIOS QSSC-S4R.QCI.01.00.0027.070120100606 07/01/2010
ffff8838245eea00 ffff88103fc63c98 ffffffff814c4a1e ffff88103fc63ca8
ffffffff814bfbab ffff88103fc63d28 ffffffff814c73e0 ffff88103933cbd4
0000000000000096 ffff88103fc63ce8 ffff88102f618000 ffff881035c01fd8
Call Trace:
<IRQ> [<ffffffff814c4a1e>] dump_stack+0x19/0x1b
[<ffffffff814bfbab>] __schedule_bug+0x46/0x54
[<ffffffff814c73e0>] __schedule+0x83/0x59c
[<ffffffff81058853>] __cond_resched+0x22/0x2d
[<ffffffff814c794b>] _cond_resched+0x14/0x1d
[<ffffffff814c6d82>] mutex_lock+0x11/0x32
[<ffffffff8101e1e9>] ? __default_send_IPI_dest_field.constprop.0+0x53/0x58
[<ffffffffa09e3f9c>] ipmi_msg_handler+0x23/0x166 [ipmi_si]
[<ffffffff812bf6e4>] deliver_response+0x55/0x5a
[<ffffffff812c0fd4>] handle_new_recv_msgs+0xb67/0xc65
[<ffffffff81007ad1>] ? read_tsc+0x9/0x19
[<ffffffff814c8620>] ? _raw_spin_lock_irq+0xa/0xc
[<ffffffffa09e1128>] ipmi_thread+0x5c/0x146 [ipmi_si]
...
Also Tony Camuso says:
We were getting occasional "Scheduling while atomic" call traces
during boot on some systems. Problem was first seen on a Cisco C210
but we were able to reproduce it on a Cisco c220m3. Setting
CONFIG_LOCKDEP and LOCKDEP_SUPPORT to 'y' exposed a lockdep around
tx_msg_lock in acpi_ipmi.c struct acpi_ipmi_device.
=================================
[ INFO: inconsistent lock state ]
2.6.32-415.el6.x86_64-debug-splck #1
---------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/3/17 [HC0[0]:SC1[1]:HE1:SE0] takes:
(&ipmi_device->tx_msg_lock){+.?...}, at: [<ffffffff81337a27>] ipmi_msg_handler+0x71/0x126
{SOFTIRQ-ON-W} state was registered at:
[<ffffffff810ba11c>] __lock_acquire+0x63c/0x1570
[<ffffffff810bb0f4>] lock_acquire+0xa4/0x120
[<ffffffff815581cc>] __mutex_lock_common+0x4c/0x400
[<ffffffff815586ea>] mutex_lock_nested+0x4a/0x60
[<ffffffff8133789d>] acpi_ipmi_space_handler+0x11b/0x234
[<ffffffff81321c62>] acpi_ev_address_space_dispatch+0x170/0x1be
The fix implemented by this change has been tested by Tony:
Tested the patch in a boot loop with lockdep debug enabled and never
saw the problem in over 400 reboots.
Reported-and-tested-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Reviewed-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull ACPI and power management fixes from Rafael Wysocki:
"All of these commits are fixes that have emerged recently and some of
them fix bugs introduced during this merge window.
Specifics:
1) ACPI-based PCI hotplug (ACPIPHP) fixes related to spurious events
After the recent ACPIPHP changes we've seen some interesting
breakage on a system that triggers device check notifications
during boot for non-existing devices. Although those
notifications are really spurious, we should be able to deal with
them nevertheless and that shouldn't introduce too much overhead.
Four commits to make that work properly.
2) Memory hotplug and hibernation mutual exclusion rework
This was maent to be a cleanup, but it happens to fix a classical
ABBA deadlock between system suspend/hibernation and ACPI memory
hotplug which is possible if they are started roughly at the same
time. Three commits rework memory hotplug so that it doesn't
acquire pm_mutex and make hibernation use device_hotplug_lock
which prevents it from racing with memory hotplug.
3) ACPI Intel LPSS (Low-Power Subsystem) driver crash fix
The ACPI LPSS driver crashes during boot on Apple Macbook Air with
Haswell that has slightly unusual BIOS configuration in which one
of the LPSS device's _CRS method doesn't return all of the
information expected by the driver. Fix from Mika Westerberg, for
stable.
4) ACPICA fix related to Store->ArgX operation
AML interpreter fix for obscure breakage that causes AML to be
executed incorrectly on some machines (observed in practice).
From Bob Moore.
5) ACPI core fix for PCI ACPI device objects lookup
There still are cases in which there is more than one ACPI device
object matching a given PCI device and we don't choose the one
that the BIOS expects us to choose, so this makes the lookup take
more criteria into account in those cases.
6) Fix to prevent cpuidle from crashing in some rare cases
If the result of cpuidle_get_driver() is NULL, which can happen on
some systems, cpuidle_driver_ref() will crash trying to use that
pointer and the Daniel Fu's fix prevents that from happening.
7) cpufreq fixes related to CPU hotplug
Stephen Boyd reported a number of concurrency problems with
cpufreq related to CPU hotplug which are addressed by a series of
fixes from Srivatsa S Bhat and Viresh Kumar.
8) cpufreq fix for time conversion in time_in_state attribute
Time conversion carried out by cpufreq when user space attempts to
read /sys/devices/system/cpu/cpu*/cpufreq/stats/time_in_state
won't work correcty if cputime_t doesn't map directly to jiffies.
Fix from Andreas Schwab.
9) Revert of a troublesome cpufreq commit
Commit 7c30ed5 (cpufreq: make sure frequency transitions are
serialized) was intended to address some known concurrency
problems in cpufreq related to the ordering of transitions, but
unfortunately it introduced several problems of its own, so I
decided to revert it now and address the original problems later
in a more robust way.
10) Intel Haswell CPU models for intel_pstate from Nell Hardcastle.
11) cpufreq fixes related to system suspend/resume
The recent cpufreq changes that made it preserve CPU sysfs
attributes over suspend/resume cycles introduced a possible NULL
pointer dereference that caused it to crash during the second
attempt to suspend. Three commits from Srivatsa S Bhat fix that
problem and a couple of related issues.
12) cpufreq locking fix
cpufreq_policy_restore() should acquire the lock for reading, but
it acquires it for writing. Fix from Lan Tianyu"
* tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits)
cpufreq: Acquire the lock in cpufreq_policy_restore() for reading
cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu
cpufreq: Restructure if/else block to avoid unintended behavior
cpufreq: Fix crash in cpufreq-stats during suspend/resume
intel_pstate: Add Haswell CPU models
Revert "cpufreq: make sure frequency transitions are serialized"
cpufreq: Use signed type for 'ret' variable, to store negative error values
cpufreq: Remove temporary fix for race between CPU hotplug and sysfs-writes
cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug
cpufreq: Invoke __cpufreq_remove_dev_finish() after releasing cpu_hotplug.lock
cpufreq: Split __cpufreq_remove_dev() into two parts
cpufreq: Fix wrong time unit conversion
cpufreq: serialize calls to __cpufreq_governor()
cpufreq: don't allow governor limits to be changed when it is disabled
ACPI / bind: Prefer device objects with _STA to those without it
ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks
ACPI / hotplug / PCI: Use _OST to notify firmware about notify status
ACPI / hotplug / PCI: Avoid doing too much for spurious notifies
ACPICA: Fix for a Store->ArgX when ArgX contains a reference to a field.
ACPI / hotplug / PCI: Don't trim devices before scanning the namespace
...
As reported at https://bugzilla.kernel.org/show_bug.cgi?id=60829,
there still are cases in which do_find_child() doesn't choose the
ACPI device object it is "expected" to choose if there are more such
objects matching one PCI device present. This particular problem may
be worked around by making do_find_child() return device obejcts witn
_STA whose result indicates that the device is enabled before device
objects without _STA if there's more than one device object to choose
from.
This change doesn't affect the case in which there's only one
matching ACPI device object per PCI device.
References: https://bugzilla.kernel.org/show_bug.cgi?id=60829
Reported-by: Peter Wu <lekensteyn@gmail.com>
Tested-by: Felix Lisczyk <felix.lisczyk@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This change fixes a problem where a Store operation to an ArgX object
that contained a reference to a field object did not complete the
automatic dereference and then write to the actual field object.
Instead, the object type of the field object was inadvertently changed
to match the type of the source operand. The new behavior will actually
write to the field object (buffer field or field unit), thus matching
the correct ACPI-defined behavior.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull i2c updates from Wolfram Sang:
"Highlights:
- OF and ACPI helpers are now included in the core, and not in
external files anymore. This removes dependency problems for
modules and is cleaner, in general.
- mv64xxx-driver gains fifo usage to support mv78230
- imx-driver overhaul to support VF610
- various cleanups, most notably related to devm_* and CONFIG_PM
usage
- driver bugfixes and smaller feature additions"
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (51 commits)
i2c: rcar: add rcar-H2 support
i2c: sirf: retry 3 times as sometimes we get random noack and timeout
i2c: sirf: support reverse direction of address
i2c: sirf: fix the typo for setting bitrate to less than 100k
i2c: sirf: we need to wait I2C_RESET status in resume
i2c: sirf: reset i2c controller early after we get a noack
i2c: designware: get SDA hold time, HCNT and LCNT configuration from ACPI
i2c: designware: make HCNT/LCNT values configurable
i2c: mpc: cleanup clock API use
i2c: pnx: fix error return code in i2c_pnx_probe()
i2c: ismt: add error return code in probe()
i2c: mv64xxx: fix typo in binding documentation
i2c: imx: use exact SoC revision to document binding
i2c: move ACPI helpers into the core
i2c: move OF helpers into the core
i2c: mv64xxx: Fix timing issue on Armada XP (errata FE-8471889)
i2c: mv64xxx: Add I2C Transaction Generator support
i2c: powermac: fix return path on error
Documentation: i2c: Fix example in instantiating-devices
i2c: tiny-usb: do not use stack as URB transfer_buffer
...
Pull PTR_RET() removal patches from Rusty Russell:
"PTR_RET() is a weird name, and led to some confusing usage. We ended
up with PTR_ERR_OR_ZERO(), and replacing or fixing all the usages.
This has been sitting in linux-next for a whole cycle"
[ There are still some PTR_RET users scattered about, with some of them
possibly being new, but most of them existing in Rusty's tree too. We
have that
#define PTR_RET(p) PTR_ERR_OR_ZERO(p)
thing in <linux/err.h>, so they continue to work for now - Linus ]
* tag 'PTR_RET-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
GFS2: Replace PTR_RET with PTR_ERR_OR_ZERO
Btrfs: volume: Replace PTR_RET with PTR_ERR_OR_ZERO
drm/cma: Replace PTR_RET with PTR_ERR_OR_ZERO
sh_veu: Replace PTR_RET with PTR_ERR_OR_ZERO
dma-buf: Replace PTR_RET with PTR_ERR_OR_ZERO
drivers/rtc: Replace PTR_RET with PTR_ERR_OR_ZERO
mm/oom_kill: remove weird use of ERR_PTR()/PTR_ERR().
staging/zcache: don't use PTR_RET().
remoteproc: don't use PTR_RET().
pinctrl: don't use PTR_RET().
acpi: Replace weird use of PTR_RET.
s390: Replace weird use of PTR_RET.
PTR_RET is now PTR_ERR_OR_ZERO(): Replace most.
PTR_RET is now PTR_ERR_OR_ZERO
Pull x86 RAS changes from Ingo Molnar:
"[ The reason for drivers/ updates is that Boris asked for the
drivers/edac/ changes to go via x86/ras in this cycle ]
Main changes:
- AMD CPUs:
. Add ECC event decoding support for new F15h models
. Various erratum fixes
. Fix single-channel on dual-channel-controllers bug.
- Intel CPUs:
. UC uncorrectable memory error parsing fix
. Add support for CMC (Corrected Machine Check) 'FF' (Firmware
First) flag in the APEI HEST
- Various cleanups and fixes"
* 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
amd64_edac: Fix incorrect wraparounds
amd64_edac: Correct erratum 505 range
cpc925_edac: Use proper array termination
x86/mce, acpi/apei: Only disable banks listed in HEST if mce is configured
amd64_edac: Get rid of boot_cpu_data accesses
amd64_edac: Add ECC decoding support for newer F15h models
x86, amd_nb: Clarify F15h, model 30h GART and L3 support
pci_ids: Add PCI device ID functions 3 and 4 for newer F15h models.
x38_edac: Make a local function static
i3200_edac: Make a local function static
x86/mce: Pay no attention to 'F' bit in MCACOD when parsing 'UC' errors
APEI/ERST: Fix error message formatting
amd64_edac: Fix single-channel setups
EDAC: Replace strict_strtol() with kstrtol()
mce: acpi/apei: Soft-offline a page on firmware GHES notification
mce: acpi/apei: Add a boot option to disable ff mode for corrected errors
mce: acpi/apei: Honour Firmware First for MCA banks listed in APEI HEST CMC
Pull pstore changes from Tony Luck:
"A big part of this is the addition of compression to the generic
pstore layer so that all backends can use the pitiful amounts of
storage they control more effectively. Three other small
fixes/cleanups too.
* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
pstore/ram: (really) fix undefined usage of rounddown_pow_of_two
pstore/ram: Read and write to the 'compressed' flag of pstore
efi-pstore: Read and write to the 'compressed' flag of pstore
erst: Read and write to the 'compressed' flag of pstore
powerpc/pseries: Read and write to the 'compressed' flag of pstore
pstore: Add file extension to pstore file if compressed
pstore: Add decompression support to pstore
pstore: Introduce new argument 'compressed' in the read callback
pstore: Add compression support to pstore
pstore/Kconfig: Select ZLIB_DEFLATE and ZLIB_INFLATE when PSTORE is selected
pstore: Add new argument 'compressed' in pstore write callback
powerpc/pseries: Remove (de)compression in nvram with pstore enabled
pstore: d_alloc_name() doesn't return an ERR_PTR
acpi/apei/erst: Add missing iounmap() on error in erst_exec_move_data()
Pull ACPI and power management updates from Rafael Wysocki:
1) ACPI-based PCI hotplug (ACPIPHP) subsystem rework and introduction
of Intel Thunderbolt support on systems that use ACPI for signalling
Thunderbolt hotplug events. This also should make ACPIPHP work in
some cases in which it was known to have problems. From
Rafael J Wysocki, Mika Westerberg and Kirill A Shutemov.
2) ACPI core code cleanups and dock station support cleanups from
Jiang Liu and Rafael J Wysocki.
3) Fixes for locking problems related to ACPI device hotplug from
Rafael J Wysocki.
4) ACPICA update to version 20130725 includig fixes, cleanups, support
for more than 256 GPEs per GPE block and a change to make the ACPI
PM Timer optional (we've seen systems without the PM Timer in the
field already). One of the fixes, related to the DeRefOf operator,
is necessary to prevent some Windows 8 oriented AML from causing
problems to happen. From Bob Moore, Lv Zheng, and Jung-uk Kim.
5) Removal of the old and long deprecated /proc/acpi/event interface
and related driver changes from Thomas Renninger.
6) ACPI and Xen changes to make the reduced hardware sleep work with
the latter from Ben Guthro.
7) ACPI video driver cleanups and a blacklist of systems that should
not tell the BIOS that they are compatible with Windows 8 (or ACPI
backlight and possibly other things will not work on them). From
Felipe Contreras.
8) Assorted ACPI fixes and cleanups from Aaron Lu, Hanjun Guo,
Kuppuswamy Sathyanarayanan, Lan Tianyu, Sachin Kamat, Tang Chen,
Toshi Kani, and Wei Yongjun.
9) cpufreq ondemand governor target frequency selection change to
reduce oscillations between min and max frequencies (essentially,
it causes the governor to choose target frequencies proportional
to load) from Stratos Karafotis.
10) cpufreq fixes allowing sysfs attributes file permissions to be
preserved over suspend/resume cycles Srivatsa S Bhat.
11) Removal of Device Tree parsing for CPU device nodes from multiple
cpufreq drivers that required some changes related to
of_get_cpu_node() to be made in a few architectures and in the
driver core. From Sudeep KarkadaNagesha.
12) cpufreq core fixes and cleanups related to mutual exclusion and
driver module references from Viresh Kumar, Lukasz Majewski and
Rafael J Wysocki.
13) Assorted cpufreq fixes and cleanups from Amit Daniel Kachhap,
Bartlomiej Zolnierkiewicz, Hanjun Guo, Jingoo Han, Joseph Lo,
Julia Lawall, Li Zhong, Mark Brown, Sascha Hauer, Stephen Boyd,
Stratos Karafotis, and Viresh Kumar.
14) Fixes to prevent race conditions in coupled cpuidle from happening
from Colin Cross.
15) cpuidle core fixes and cleanups from Daniel Lezcano and
Tuukka Tikkanen.
16) Assorted cpuidle fixes and cleanups from Daniel Lezcano,
Geert Uytterhoeven, Jingoo Han, Julia Lawall, Linus Walleij,
and Sahara.
17) System sleep tracing changes from Todd E Brandt and Shuah Khan.
18) PNP subsystem conversion to using struct dev_pm_ops for power
management from Shuah Khan.
* tag 'pm+acpi-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (217 commits)
cpufreq: Don't use smp_processor_id() in preemptible context
cpuidle: coupled: fix race condition between pokes and safe state
cpuidle: coupled: abort idle if pokes are pending
cpuidle: coupled: disable interrupts after entering safe state
ACPI / hotplug: Remove containers synchronously
driver core / ACPI: Avoid device hot remove locking issues
cpufreq: governor: Fix typos in comments
cpufreq: governors: Remove duplicate check of target freq in supported range
cpufreq: Fix timer/workqueue corruption due to double queueing
ACPI / EC: Add ASUSTEK L4R to quirk list in order to validate ECDT
ACPI / thermal: Add check of "_TZD" availability and evaluating result
cpufreq: imx6q: Fix clock enable balance
ACPI: blacklist win8 OSI for buggy laptops
cpufreq: tegra: fix the wrong clock name
cpuidle: Change struct menu_device field types
cpuidle: Add a comment warning about possible overflow
cpuidle: Fix variable domains in get_typical_interval()
cpuidle: Fix menu_device->intervals type
cpuidle: CodingStyle: Break up multiple assignments on single line
cpuidle: Check called function parameter in get_typical_interval()
...
Pull driver core patches from Greg KH:
"Here's the big driver core pull request for 3.12-rc1.
Lots of tiny changes here fixing up the way sysfs attributes are
created, to try to make drivers simpler, and fix a whole class race
conditions with creations of device attributes after the device was
announced to userspace.
All the various pieces are acked by the different subsystem
maintainers"
* tag 'driver-core-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (119 commits)
firmware loader: fix pending_fw_head list corruption
drivers/base/memory.c: introduce help macro to_memory_block
dynamic debug: line queries failing due to uninitialized local variable
sysfs: sysfs_create_groups returns a value.
debugfs: provide debugfs_create_x64() when disabled
rbd: convert bus code to use bus_groups
firmware: dcdbas: use binary attribute groups
sysfs: add sysfs_create/remove_groups for when SYSFS is not enabled
driver core: add #include <linux/sysfs.h> to core files.
HID: convert bus code to use dev_groups
Input: serio: convert bus code to use drv_groups
Input: gameport: convert bus code to use drv_groups
driver core: firmware: use __ATTR_RW()
driver core: core: use DEVICE_ATTR_RO
driver core: bus: use DRIVER_ATTR_WO()
driver core: create write-only attribute macros for devices and drivers
sysfs: create __ATTR_WO()
driver-core: platform: convert bus code to use dev_groups
workqueue: convert bus code to use dev_groups
MEI: convert bus code to use dev_groups
...
Intel LPSS devices that are enumerated from ACPI have both MMIO and IRQ
resources returned in their _CRS method. However, Apple Macbook Air with
Haswell has LPSS devices enumerated from PCI bus instead and _CRS method
returns only an interrupt number (but the device has _HID set that causes
the scan handler to match it).
The current ACPI / LPSS code sets pdata->dev_desc only when MMIO resource
is found for the device and in case of Macbook Air it is never found. That
leads to a NULL pointer dereference in register_device_clock().
Correct this by always setting the pdata->dev_desc.
Reported-and-tested-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Change the ordering of device hotplug locks in scan.c so that
acpi_scan_lock is always acquired after device_hotplug_lock.
This will make it possible to use device_hotplug_lock around some
code paths that acquire acpi_scan_lock safely (most importantly
system suspend and hibernation). Apart from that, acpi_scan_lock
is platform-specific and device_hotplug_lock is general, so the
new ordering appears to be more appropriate from the overall
design viewpoint.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
* acpi-assorted:
ACPI / EC: Add ASUSTEK L4R to quirk list in order to validate ECDT
ACPI / thermal: Add check of "_TZD" availability and evaluating result
* pci/misc:
PCI/ACPI: Fix _OSC ordering to allow PCIe hotplug use when available
PCI: exynos: Add I/O access wrappers
PCI: designware: Drop "addr" arg from dw_pcie_readl_rc()/dw_pcie_writel_rc()
This fixes the problem of acpiphp claiming slots that should be managed
by pciehp, which may keep ExpressCard slots from working.
The acpiphp driver claims PCIe slots unless the BIOS has granted us
control of PCIe native hotplug via _OSC. Prior to v3.10, the acpiphp
.add method (add_bridge()) was always called *after* we had requested
native hotplug control with _OSC.
But after 3b63aaa70e ("PCI: acpiphp: Do not use ACPI PCI subdriver
mechanism"), which appeared in v3.10, acpiphp initialization is done
during the bus scan via the pcibios_add_bus() hook, and this happens
*before* we request native hotplug control.
Therefore, acpiphp doesn't know yet whether the BIOS will grant control,
and it claims slots that we should be handling with native hotplug.
This patch requests native hotplug control earlier, so we know whether
the BIOS granted it to us before we initialize acpiphp.
To avoid reintroducing the ASPM issue fixed by b8178f130e ('Revert
"PCI/ACPI: Request _OSC control before scanning PCI root bus"'), we run
_OSC earlier but defer the actual ASPM calls until after the bus scan is
complete.
Tested successfully by myself.
[bhelgaas: changelog, mark for stable]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60736
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
CC: stable@vger.kernel.org # v3.10+
CC: Len Brown <lenb@kernel.org>
CC: "Rafael J. Wysocki" <rjw@sisk.pl>
The current protocol for handling hot remove of containers is very
fragile and causes acpi_eject_store() to acquire acpi_scan_lock
which may deadlock with the removal of the device that it is called
for (the reason is that device sysfs attributes cannot be removed
while their callbacks are being executed and ACPI device objects
are removed under acpi_scan_lock).
The problem is related to the fact that containers are handled by
acpi_bus_device_eject() in a special way, which is to emit an
offline uevent instead of just removing the container. Then, user
space is expected to handle that uevent and use the container's
"eject" attribute to actually remove it. That is fragile, because
user space may fail to complete the ejection (for example, by not
using the container's "eject" attribute at all) leaving the BIOS
kind of in a limbo. Moreover, if the eject event is not signaled
for a container itself, but for its parent device object (or
generally, for an ancestor above it in the ACPI namespace), the
container will be removed straight away without doing that whole
dance.
For this reason, modify acpi_bus_device_eject() to remove containers
synchronously like any other objects (user space will get its uevent
anyway in case it does some other things in response to it) and
remove the eject_pending ACPI device flag that is not used any more.
This way acpi_eject_store() doesn't have a reason to acquire
acpi_scan_lock any more and one possible deadlock scenario goes
away (plus the code is simplified a bit).
Reported-and-tested-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Rafael J. Wysocki
Hanjun Guo
Lv Zheng
Linus Torvalds
Bob Moore
Mika Westerberg
Bjorn Helgaas
Neil Horman
Lan Tianyu