In case a card is physically yanked out, it should immediately be removed,
regardless of the "surprise" capability bit. Thus:
- Always handle the physical removal - regardless of the "surprise" bit.
- Don't use "surprise" capability when making decisions about enabling
presence detect notifications.
- Reword the comments to indicate the intent.
Signed-off-by: Rajat Jain <rajatxjain@gmail.com>
Signed-off-by: Rajat Jain <rajatjain@juniper.net>
Signed-off-by: Guenter Roeck <groeck@juniper.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
If we found device already exists during hot add device, we should leave
it, not turn the slot off.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Today it is there is no protection around pciehp_enable_slot() and
pciehp_disable_slot() to ensure that they complete before another
hot-plug operation can be done on that particular slot.
This patch introduces the slot->hotplug_lock to ensure that any hotplug
operations (add / remove) complete before another hotplug event can begin
processing on that particular slot.
Signed-off-by: Rajat Jain <rajatxjain@gmail.com>
Signed-off-by: Rajat Jain <rajatjain@juniper.net>
Signed-off-by: Guenter Roeck <groeck@juniper.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Today, this is how all the hotplug and unplug events work:
Hotplug / Removal needs to be done
=> Set slot->state (protected by slot->lock) to either
POWERON_STATE (for enabling) or POWEROFF_STATE (for disabling).
=> Submit the work item for pciehp_power_thread() to slot->wq.
Problem:
There is a problem if the hotplug events can happen fast enough that
they do not give SW enough time to add or remove the new devices.
=> Assume: Event for unplug comes (e.g. surprise removal). But
before the pciehp_power_thread() work item was executed, the
card was replaced by another card, causing surprise hotplug event.
=> What goes wrong:
=> The hot-removal event sets slot->state to POWEROFF_STATE, and
schedules the pciehp_power_thread().
=> The hot-add event sets slot->state to POWERON_STATE, and
schedules the pciehp_power_thread().
=> Now the pciehp_power_thread() is scheduled twice, and on both
occasions it will find POWERON_STATE and will try to add the
devices on the slot, and will fail complaining that the devices
already exist.
=> Why this is a problem: If the device was replaced between the hot
removal and hot-add, then we should unload the old driver and
reload the new one. This does not happen today. The kernel or the
driver is not even aware that the device was replaced.
The problem is that the pciehp_power_thread() only looks at the
slot->state which would only contain the *latest* state - not
the actual event (add / remove) that was the intent of the IRQ
handler who submitted the work.
What this patch does:
=> Hotplug events pass on an actual request (for addition or removal)
to pciehp_power_thread() which is local to that work item
submission.
=> pciehp_power_thread() does not need to look at slote->state and
hence no locks needed in that.
=> Essentially this results in all the hotplug and unplug events
"replayed" by pciehp_power_thread().
Signed-off-by: Rajat Jain <rajatxjain@gmail.com>
Signed-off-by: Rajat Jain <rajatjain@juniper.net>
Signed-off-by: Guenter Roeck <groeck@juniper.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
It does not make much sense to refuse to disable a slot if an adapter is
not present or the latch is open. If an adapter is not present, it provides
an even better reason to disable the device slot.
This is specially a problem for link state hot-plug, because some ports use
in band mechanism for presence detection. Thus when link goes down,
presence detect also goes down. We _want_ that the removal should take
place in such case.
Thus remove the checks for adapter and latch in pciehp_disable_slot()
Signed-off-by: Rajat Jain <rajatxjain@gmail.com>
Signed-off-by: Rajat Jain <rajatjain@juniper.net>
Signed-off-by: Guenter Roeck <groeck@juniper.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
A lot of systems do not have the fancy buttons and LEDs, and instead
want to rely only on the Link state change events to drive the hotplug
and removal state machinery.
(http://www.spinics.net/lists/hotplug/msg05802.html)
This patch adds support for that functionality. Here are the details
about the patch itself:
* Define and use interrupt events for linkup / linkdown.
* Make the pcie_isr() also look at link events, and direct control to
corresponding (new) link state change handler function.
* Introduce the functions to handle link-up and link-down events and
queue the add / removal work in the slot->wq to be processed by
pciehp_power_thread()
As a side note, this patch also fixes the bug
https://bugzilla.kernel.org/show_bug.cgi?id=65521 "pciehp ignores Data Link
Layer State Changed bit."
Signed-off-by: Rajat Jain <rajatxjain@gmail.com>
Signed-off-by: Rajat Jain <rajatjain@juniper.net>
Signed-off-by: Guenter Roeck <groeck@juniper.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously, the caller checked ATTN_LED() or PWR_LED() to see whether the
slot has indicators before setting the indicator state. That clutters the
caller unnecessarily, so this moves the test inside the callees. The test
may not even be necessary; per spec it should be harmless to try to turn on
a non-existent LED. But checking first does avoid unnecessary hotplug
commands.
No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
These functions:
pcie_enable_notification()
pciehp_power_off_slot()
pciehp_get_power_status()
pciehp_get_attention_status()
pciehp_set_attention_status()
pciehp_get_latch_status()
pciehp_get_adapter_status()
pcie_write_cmd()
now always return success, so this patch makes them void and drops the
error-checking code in their callers.
No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
When we have a hotplug-capable PCIe port with a second hotplug-capable
PCIe port below it, removing the device below the upstream port causes
a deadlock.
The deadlock happens because we use the pciehp_wq workqueue to run
pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices
below the upstream port. When we remove the downstream PCIe port, we call
pciehp_remove(), the pciehp driver's .remove() method. That calls
flush_workqueue(pciehp_wq), which deadlocks because the
pciehp_power_thread() work item is still running.
This patch avoids the deadlock by creating a workqueue for every PCIe port
and removing the single shared workqueue.
Here's the call path that leads to the deadlock:
pciehp_queue_pushbutton_work
queue_work(pciehp_wq) # queue pciehp_power_thread
...
pciehp_power_thread
pciehp_disable_slot
remove_board
pciehp_unconfigure_device
pci_stop_and_remove_bus_device
...
pciehp_remove # pciehp driver .remove method
pciehp_release_ctrl
pcie_cleanup_slot
flush_workqueue(pciehp_wq)
This is fairly urgent because it can be caused by simply unplugging a
Thunderbolt adapter, as reported by Daniel below.
[bhelgaas: changelog]
Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.com
Reported-and-tested-by: Daniel J Blueman <daniel@quora.org>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
Use non-ordered workqueue for attention button events.
Attention button events on each slot can be handled asynchronously. So
we should use non-ordered workqueue. This patch also removes ordered
workqueue in pciehp as a result.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We need to wait for 1000 ms after Data Link Layer Link Active (DLLLA)
bit reads 1b before sending configuration request. Currently pciehp
does this wait after checking Link Training (LT) bit. But we need it
before checking LT bit because LT is still set even after DLLLA bit is
set on some platforms.
Acked-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Naoki Yanagimoto reported that configuration read on some hot-added
PCIe device returns invalid value. This patch fixes this problem.
According to the PCIe spec, software must wait for at least 1 second
to judge if the hot-added device is broken after Data Link Layer State
Changed Event. This patch changes pciehp driver to wait for 1 second
after the Data Link Layer State Changed Event is detected before
initiating a configuration access instead of 100 ms.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Naoki Yanagimoto <yanagimoto@np.css.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* Rename pciehp_wq to pciehp_ordered_wq and add non-ordered pciehp_wq
which is used instead of the system workqueue. This is to remove
the use of flush_scheduled_work() which is deprecated and scheduled
for removal.
* With cmwq in place, there's no point in creating workqueues lazily.
Create both pciehp_wq and pciehp_ordered_wq upfront.
* Include workqueue.h from pciehp.h.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Stanse found a cut&pasted memory leak in pciehp_queue_pushbutton_work
and shpchp_queue_pushbutton_work. info is not freed/assigned on all
paths. Fix that.
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Enabling power fault detected event notification in current pciehp
might cause power fault interrupt storm on some machines. On those
machines. On those machines, power fault detected bit in the slot
status register was set again immediately when it is cleared in the
interrupt service routine, and next power fault detected interrupt was
notified again. Therefore, disable power fault detected event
notification for now.
This patch also removes unnecessary handling for power fault cleared
event because this event is not supported by PCIe spec.
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Current pciehp returns successfully on read/write failure with dummy
state values. It should return error instead.
With this patch, pciehp no longer uses hotplug_slot_info data
structure. So this also removes hotplug_slot_info related code. But
note that it still allocates hotplug_slot_info because it is required
by pci hotplug core.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The struct hpc_ops seems a set of hooks to controller specific
routines. But, it is meaningless because no hotplug controller driver
follows this framework.
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Since we have a pointer to pcie_device in struct controller, we don't
need a pointer to pci_dev.
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The crit_sect mutex defined in struct controller is to serialize
hot-plug operations against multiple slots under the same bus. But,
since PCIe doesnstream port has only one slot at most, it is
meaningless and we don't need it.
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Since the device number of the hot-slot under the PCIe downstream port
is always 0, the slot_device_offset field in the slot is meaningless
and we don't need it.
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The hp_slot field is to identify the slot under the same
controller. But, since PCIe downstream port has only one slot at most,
it is meaningless and we don't need it.
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The device field in the struct slot is not necessary because it is
always 0 in pciehp driver.
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The bus field in struct slot is not necessary.
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
There is a very old quirk for the intel E7502 E7320 and E7525 memory
controller hubs that disables usage of msi interrupts on pcie hotplug
bridges of those devices, and disables changing the affinity of irqs.
Today all we have to do to disable msi on a specific device is to set
dev->no_msi, which is much more straightforward than the previous
logic.
The re-running of this fixup after pci hotplug happens below these
devices is totally bogus. All of the state we change is pure software
state and we don't change the hardware at all. Which means hotplug on
the lower devices doesn't have a chance to change this state. So we
can safely remove the special case from the pciehp driver and the pcie
portdriver.
I suspect the special case was someone's expermental debug code that
slipped in. Certainly it isn't mentioned in commit
6fb8880a61510295aece04a542767161f624dffe aka BKrev:
41966101LJ_ogfOU0m2aE6teZfQnuQ where the code first appears.
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT
This will make hardirq.h inclusion cheaper for every PREEMPT=n config
(which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The pciehp driver waits for 1000 msec after turning power off to make
sure the power has been completely removed. But this 1000 msec wait is
not needed if a slot doesn't implement power control because software
cannot control the power. Power will be automatically removed at adapter
removal time on such a slot
Tested-by: "Phil Endecott" <phil_pibbu_endecott@chezphil.org>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This patch refines messages in pciehp module. The main changes are as
follows:
- remove the trailing "."
- remove __func__ as much as possible
- capitalize the first letter of messages
- show PCI device address including its domain
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This patch adds polling mechanism for Data Link Layer Link Active bit
after turning power on, instead of waiting for 1000 msec. This reduces
reduce the unnecessary long wait.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
We do not need to manage our own name parameter, especially since
the PCI core can change it on our behalf, in the case of duplicate
slot names.
Remove 'name' from pciehp's version of struct slot, and remove
unused 'task_list' as well.
Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
According to the PCI Express specification, we must wait for at least
1 second after turning power off before taking any action that relies
on power having been removed from the slot/adapter. For this, current
pciehp wait for 1 second after issuing the power off command in
hpc_power_off_slot() function. But waiting for 1 second in
hpc_power_off_slot() can make pciehp probing slow-down because pciehp
probe code calls hpc_power_off_slot() if the slot is not occupied just
in case. We don't need to wait for 1 second at the pciehp probe time
because there is no action on that empty slot. So move 1 second wait
from hpc_power_off_slot() to the caller of hpc_power_off_slot().
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Current pciehp saves only 8bits of Slot Capability registers in
ctrl->ctrlcap. But it refers more than 8bit for checking EMI capability.
It is clearly a bug and EMI would never work. To fix this problem,
this patch saves full Slot Capability contens in ctrl->slot_cap. It also
reduce the redundant reads of Slot Capability register. And this pach
also cleans up the macros to check the slot capabilitys (e.g. MRL_SENS(),
and so on).
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After turning power off, we must wait for at least 1 second *before*
LED operation.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make use of the previously split out pcie_init_enable_events() function
to reinitialize the hotplug hardware on resume from suspend, but only
when pciehp_force==1. Otherwise behaviour is unmodified.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix pciehp_probe() to deal with ExpressCard cards
that were inserted prior to the driver being loaded.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
According to the specification, we must wait for at least 1 second
after turning power off before taking any action that relies on power
having been removed from the slot/adapter.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The event handler of PCIEHP driver is unnecessarily very complex. In
addition, current event handler can only a fixed number of events at
the same time, and some of events would be lost if several number of
events happened at the same time.
This patch simplify the event handler using 'work queue', and it also
fix the above-mentioned issue.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch cleans up the code to wait for command completion.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch cleans up pciehp.h. This has no functional change.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The struct php_ctlr seems to be only for complicating codes. This
patch removes struct php_ctlr and related codes.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
this was spotted by coverity (cid #819). We dereference p_slot
earlier in the function, and i found no way it could become NULL
anywhere.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes the problem that system will panic if multiple power
on/off operations are issued to the same slot in parallel. This
problem can be easily reproduced by commands below.
# while true; do echo 1 > power; echo 0 > power; done &
# while true; do echo 1 > power; echo 0 > power; done &
The cause is lack of locking for enable/disable operations. This patch
fixes this problem.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
