commit 3a32bd72d7 upstream.
We've converted cgroup to kernfs so cgroup won't be intertwined with
vfs objects and locking, but there are dark areas.
Run two instances of this script concurrently:
for ((; ;))
{
mount -t cgroup -o cpuacct xxx /cgroup
umount /cgroup
}
After a while, I saw two mount processes were stuck at retrying, because
they were waiting for a subsystem to become free, but the root associated
with this subsystem never got freed.
This can happen, if thread A is in the process of killing superblock but
hasn't called percpu_ref_kill(), and at this time thread B is mounting
the same cgroup root and finds the root in the root list and performs
percpu_ref_try_get().
To fix this, we try to increase both the refcnt of the superblock and the
percpu refcnt of cgroup root.
v2:
- we should try to get both the superblock refcnt and cgroup_root refcnt,
because cgroup_root may have no superblock assosiated with it.
- adjust/add comments.
tj: Updated comments. Renamed @sb to @pinned_sb.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
[lizf: Backported to 3.15:
- Adjust context
- s/percpu_tryget_live/atomic_inc_not_zero/]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4e26445faa upstream.
kernfs_pin_sb() tries to get a refcnt of the superblock.
This will be used by cgroupfs.
v2:
- make kernfs_pin_sb() return the superblock.
- drop kernfs_drop_sb().
tj: Updated the comment a bit.
[ This is a prerequisite for a bugfix. ]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7d568a8383 upstream.
Currently, there's no way to find out which super_blocks are
associated with a given kernfs_root. Let's implement it - the planned
inotify extension to kernfs_notify() needs it.
Make kernfs_super_info point back to the super_block and chain it at
kernfs_root->supers.
Signed-off-by: Tejun Heo <tj@kernel.org>
[lizf: Backported to 3.15: Adjust context]
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 970317aa48 upstream.
# cat test.sh
#! /bin/bash
mount -t cgroup -o cpu xxx /cgroup
umount /cgroup
mount -t cgroup -o cpu,cpuacct xxx /cgroup
umount /cgroup
# ./test.sh
mount: xxx already mounted or /cgroup busy
mount: according to mtab, xxx is already mounted on /cgroup
It's because the cgroupfs_root of the first mount was under destruction
asynchronously.
Fix this by delaying and then retrying mount for this case.
v3:
- put the refcnt immediately after getting it. (Tejun)
v2:
- use percpu_ref_tryget_live() rather that introducing
percpu_ref_alive(). (Tejun)
- adjust comment.
tj: Updated the comment a bit.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
[lizf: Backported to 3.15:
- s/percpu_ref_tryget_live/atomic_inc_not_zero/
- Use goto instead of calling restart_syscall()
- Add cgroup_tree_mutex]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ce9ccb17ef upstream.
The commit 6c167f582e ("i40e: Refactor and cleanup i40e_open(),
adding i40e_vsi_open()") introduced a new function i40e_vsi_open()
with the regression by a typo. Due to the commit, the wrong error
code would be passed to i40e_open(). Fix this error in
i40e_vsi_open() by turning the macro into a negative value so that
i40e_open() could return the pertinent error code correctly.
Fixes: 6c167f582e ("i40e: Refactor and cleanup i40e_open(), adding i40e_vsi_open()")
Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8b8b36834d upstream.
The per_cpu buffers are created one per possible CPU. But these do
not mean that those CPUs are online, nor do they even exist.
With the addition of the ring buffer polling, it assumes that the
caller polls on an existing buffer. But this is not the case if
the user reads trace_pipe from a CPU that does not exist, and this
causes the kernel to crash.
Simple fix is to check the cpu against buffer bitmask against to see
if the buffer was allocated or not and return -ENODEV if it is
not.
More updates were done to pass the -ENODEV back up to userspace.
Link: http://lkml.kernel.org/r/5393DB61.6060707@oracle.com
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0986c1a55c upstream.
When we set the valid bit on invalid GART entries they are
loaded into the TLB when an adjacent entry is loaded. This
poisons the TLB with invalid entries which are sometimes
not correctly removed on TLB flush.
For stable inclusion the patch probably needs to be modified a bit.
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f9ae9cf5d7 upstream.
Commit 007649375f ("ext4: initialize multi-block allocator before
checking block descriptors") causes the block group descriptor's count
of the number of free blocks to become inconsistent with the number of
free blocks in the allocation bitmap. This is a harmless form of fs
corruption, but it causes the kernel to potentially remount the file
system read-only, or to panic, depending on the file systems's error
behavior.
Thanks to Eric Whitney for his tireless work to reproduce and to find
the guilty commit.
Fixes: 007649375f ("ext4: initialize multi-block allocator before checking block descriptors"
Reported-by: David Jander <david@protonic.nl>
Reported-by: Matteo Croce <technoboy85@gmail.com>
Tested-by: Eric Whitney <enwlinux@gmail.com>
Suggested-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5dd214248f upstream.
The mount manpage says of the max_batch_time option,
This optimization can be turned off entirely
by setting max_batch_time to 0.
But the code doesn't do that. So fix the code to do
that.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 94d4c066a4 upstream.
We are spending a lot of time explaining to users what this error
means. Let's try to improve the message to avoid this problem.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ae0f78de2c upstream.
Make it clear that values printed are times, and that it is error
since last fsck. Also add note about fsck version required.
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 61c219f581 upstream.
The first time that we allocate from an uninitialized inode allocation
bitmap, if the block allocation bitmap is also uninitalized, we need
to get write access to the block group descriptor before we start
modifying the block group descriptor flags and updating the free block
count, etc. Otherwise, there is the potential of a bad journal
checksum (if journal checksums are enabled), and of the file system
becoming inconsistent if we crash at exactly the wrong time.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d066c946a8 upstream.
pci_wait_for_pending() uses word access, so we shouldn't be passing
an offset that is only byte aligned. Use the control register offset
instead, shifting the mask to match.
Fixes: d0b4cc4e32 ("PCI: Wrong register used to check pending traffic")
Fixes: 157e876ffe ("PCI: Add pci_wait_for_pending() (refactor pci_wait_for_pending_transaction())
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 179e847167 upstream.
Ensure that cpu->cpu is set before writing MSR_IA32_PERF_CTL during CPU
initialization. Otherwise only cpu0 has its P-state set and all other
cores are left with their values unchanged.
In most cases, this is not too serious because the P-states will be set
correctly when the timer function is run. But when the default governor
is set to performance, the per-CPU current_pstate stays the same forever
and no attempts are made to write the MSRs again.
Signed-off-by: Vincent Minet <vincent@vincent-minet.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dd5fbf70f9 upstream.
If turbo is disabled in the BIOS bit 38 should be set in
MSR_IA32_MISC_ENABLE register per section 14.3.2.1 of the SDM Vol 3
document 325384-050US Feb 2014. If this bit is set do *not* attempt
to disable trubo via the MSR_IA32_PERF_CTL register. On some systems
trying to disable turbo via MSR_IA32_PERF_CTL will cause subsequent
writes to MSR_IA32_PERF_CTL not take affect, in fact reading
MSR_IA32_PERF_CTL will not show the IDA/Turbo DISENGAGE bit(32) as
set. A write of bit 32 to zero returns to normal operation.
Also deal with the case where the processor does not support
turbo and the BIOS does not report the fact in MSR_IA32_MISC_ENABLE
but does report the max and turbo P states as the same value.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=64251
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c16ed06024 upstream.
Commit 21855ff5 (intel_pstate: Set turbo VID for BayTrail) introduced
setting the turbo VID which is required to prevent a machine check on
some Baytrail SKUs under heavy graphics based workloads. The
docmumentation update that brought the requirement to light also
changed the bit mask used for enumerating P state and VID values from
0x7f to 0x3f.
This change returns the mask value to 0x7f.
Tested with the Intel NUC DN2820FYK,
BIOS version FYBYT10H.86A.0034.2014.0513.1413 with v3.16-rc1 and
v3.14.8 kernel versions.
Fixes: 21855ff5 (intel_pstate: Set turbo VID for BayTrail)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=77951
Reported-and-tested-by: Rune Reterson <rune@megahurts.dk>
Reported-and-tested-by: Eric Eickmeyer <erich@ericheickmeyer.com>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit acfe0ad74d upstream.
The commit 2c140a246d ("dm: allow remove to be deferred") introduced a
deferred removal feature for the device mapper. When this feature is
used (by passing a flag DM_DEFERRED_REMOVE to DM_DEV_REMOVE_CMD ioctl)
and the user tries to remove a device that is currently in use, the
device will be removed automatically in the future when the last user
closes it.
Device mapper used the system workqueue to perform deferred removals.
However, some targets (dm-raid1, dm-mpath, dm-stripe) flush work items
scheduled for the system workqueue from their destructor. If the
destructor itself is called from the system workqueue during deferred
removal, it introduces a possible deadlock - the workqueue tries to flush
itself.
Fix this possible deadlock by introducing a new workqueue for deferred
removals. We allocate just one workqueue for all dm targets. The
ability of dm targets to process IOs isn't dependent on deferred removal
of unused targets, so a deadlock due to shared workqueue isn't possible.
Also, cleanup local_init() to eliminate potential for returning success
on failure.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 10f1d5d111 upstream.
There's a race condition between the atomic_dec_and_test(&io->count)
in dec_count() and the waking of the sync_io() thread. If the thread
is spuriously woken immediately after the decrement it may exit,
making the on stack io struct invalid, yet the dec_count could still
be using it.
Fix this race by using a completion in sync_io() and dec_count().
Reported-by: Minfei Huang <huangminfei@ucloud.cn>
Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7a7a3b45fe upstream.
Commit e80991773 ("dm mpath: push back requests instead of queueing")
modified multipath_busy() to return true if !pg_ready(). pg_ready()
checks the current state of the multipath device and may return false
even if a new IO is needed to change the state.
Bart Van Assche reported that he had multipath IO lockup when he was
performing cable pull tests. Analysis showed that the multipath
device had a single path group with both paths active, but that the
path group itself was not active. During the multipath device state
transitions 'queue_io' got set but nothing could clear it. Clearing
'queue_io' only happens in __choose_pgpath(), but it won't be called
if multipath_busy() returns true due to pg_ready() returning false
when 'queue_io' is set.
As such the !pg_ready() check in multipath_busy() is wrong because new
IO will not be sent to multipath target and the multipath state change
won't happen. That results in multipath IO lockup.
The intent of multipath_busy() is to avoid unnecessary cycles of
dequeue + request_fn + requeue if it is known that the multipath
device will requeue.
Such "busy" situations would be:
- path group is being activated
- there is no path and the multipath is setup to requeue if no path
Fix multipath_busy() to return "busy" early only for these specific
situations.
Reported-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit affb1aff30 upstream.
Starting with Win8, we have implemented several optimizations to improve the
scalability and performance of the VMBUS transport between the Host and the
Guest. Some of the non-performance critical services cannot leverage these
optimization since they only read and process one message at a time.
Make adjustments to the callback dispatch code to account for the way
non-performance critical drivers handle reading of the channel.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c556bcddc7 upstream.
The HDMI PLL input to the tv mux is supposed to be 3, not 2. Fix
the code so that we can properly select the HDMI PLL.
Fixes: 6d00b56fe "clk: qcom: Add support for MSM8960's multimedia clock controller (MMCC)"
Reported-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e73b49f1c4 upstream.
Prevent resources from being freed twice in case device_add() call
fails within phy_create(). Also use ida_simple_remove() instead of
ida_remove() as we had used ida_simple_get() to allocate the ida.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fa2ec3ea10 upstream.
include/linux/sched.h implements TASK_SIZE_OF as TASK_SIZE if it
is not set by the architecture headers. TASK_SIZE uses the
current task to determine the size of the virtual address space.
On a 64-bit kernel this will cause reading /proc/pid/pagemap of a
64-bit process from a 32-bit process to return EOF when it reads
past 0xffffffff.
Implement TASK_SIZE_OF exactly the same as TASK_SIZE with
test_tsk_thread_flag instead of test_thread_flag.
Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cfe82d4f45 upstream.
Byte-to-bit-count computation is only partly converted to big-endian and is
mixing in CPU-endian values. Problem was noticed by sparce with warning:
CHECK arch/x86/crypto/sha512_ssse3_glue.c
arch/x86/crypto/sha512_ssse3_glue.c:144:19: warning: restricted __be64 degrades to integer
arch/x86/crypto/sha512_ssse3_glue.c:144:17: warning: incorrect type in assignment (different base types)
arch/x86/crypto/sha512_ssse3_glue.c:144:17: expected restricted __be64 <noident>
arch/x86/crypto/sha512_ssse3_glue.c:144:17: got unsigned long long
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5a90af67c2 upstream.
Since commtit 8a7b1227e3 (cpufreq: davinci: move cpufreq driver to
drivers/cpufreq) this added dependancy only for CONFIG_ARCH_DAVINCI_DA850
where as davinci_cpufreq_init() call is used by all davinci platform.
This patch fixes following build error:
arch/arm/mach-davinci/built-in.o: In function `davinci_init_late':
:(.init.text+0x928): undefined reference to `davinci_cpufreq_init'
make: *** [vmlinux] Error 1
Fixes: 8a7b1227e3 (cpufreq: davinci: move cpufreq driver to drivers/cpufreq)
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b50a6c584b upstream.
On POWER8 when switching to a KVM guest we set bits in MMCR2 to freeze
the PMU counters. Aside from on boot they are then never reset,
resulting in stuck perf counters for any user in the guest or host.
We now set MMCR2 to 0 whenever enabling the PMU, which provides a sane
state for perf to use the PMU counters under either the guest or the
host.
This was manifesting as a bug with ppc64_cpu --frequency:
$ sudo ppc64_cpu --frequency
WARNING: couldn't run on cpu 0
WARNING: couldn't run on cpu 8
...
WARNING: couldn't run on cpu 144
WARNING: couldn't run on cpu 152
min: 18446744073.710 GHz (cpu -1)
max: 0.000 GHz (cpu -1)
avg: 0.000 GHz
The command uses a perf counter to measure CPU cycles over a fixed
amount of time, in order to approximate the frequency of the machine.
The counters were returning zero once a guest was started, regardless of
weather it was still running or had been shut down.
By dumping the value of MMCR2, it was observed that once a guest is
running MMCR2 is set to 1s - which stops counters from running:
$ sudo sh -c 'echo p > /proc/sysrq-trigger'
CPU: 0 PMU registers, ppmu = POWER8 n_counters = 6
PMC1: 5b635e38 PMC2: 00000000 PMC3: 00000000 PMC4: 00000000
PMC5: 1bf5a646 PMC6: 5793d378 PMC7: deadbeef PMC8: deadbeef
MMCR0: 0000000080000000 MMCR1: 000000001e000000 MMCRA: 0000040000000000
MMCR2: fffffffffffffc00 EBBHR: 0000000000000000
EBBRR: 0000000000000000 BESCR: 0000000000000000
SIAR: 00000000000a51cc SDAR: c00000000fc40000 SIER: 0000000001000000
This is done unconditionally in book3s_hv_interrupts.S upon entering the
guest, and the original value is only save/restored if the host has
indicated it was using the PMU. This is okay, however the user of the
PMU needs to ensure that it is in a defined state when it starts using
it.
Fixes: e05b9b9e5c ("powerpc/perf: Power8 PMU support")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4d9690dd56 upstream.
Instead of separate bits for every POWER8 PMU feature, have a single one
for v2.07 of the architecture.
This saves us adding a MMCR2 define for a future patch.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f56029410a upstream.
We are seeing a lot of PMU warnings on POWER8:
Can't find PMC that caused IRQ
Looking closer, the active PMC is 0 at this point and we took a PMU
exception on the transition from negative to 0. Some versions of POWER8
have an issue where they edge detect and not level detect PMC overflows.
A number of places program the PMC with (0x80000000 - period_left),
where period_left can be negative. We can either fix all of these or
just ensure that period_left is always >= 1.
This patch takes the second option.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f73128f4f6 upstream.
These two registers are already saved in the block above. Aside from
being unnecessary, by the time we get down to the second save location
r8 no longer contains MMCR2, so we are clobbering the saved value with
PMC5.
MMCR2 primarily consists of counter freeze bits. So restoring the value
of PMC5 into MMCR2 will most likely have the effect of freezing
counters.
Fixes: 72cde5a88d ("KVM: PPC: Book3S HV: Save/restore host PMU registers that are new in POWER8")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c0d653412f upstream.
There is a race condition in ec_transaction_completed().
When ec_transaction_completed() is called in the GPE handler, it could
return true because of (ec->curr == NULL). Then the wake_up() invocation
could complete the next command unexpectedly since there is no lock between
the 2 invocations. With the previous cleanup, the IBF=0 waiter race need
not be handled any more. It's now safe to return a flag from
advance_condition() to indicate the requirement of wakeup, the flag is
returned from a locked context.
The ec_transaction_completed() is now only invoked by the ec_poll() where
the ec->curr is ensured to be different from NULL.
After cleaning up, the EVT_SCI=1 check should be moved out of the wakeup
condition so that an EVT_SCI raised with (ec->curr == NULL) can trigger a
QR_SC command.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: Barton Xu <tank.xuhan@gmail.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f92fca0060 upstream.
Move the first command byte write into advance_transaction() so that all
EC register accesses that can affect the command processing state machine
can happen in this asynchronous state machine advancement function.
The advance_transaction() function then can be a complete implementation
of an asyncrhonous transaction for a single command so that:
1. The first command byte can be written in the interrupt context;
2. The command completion waiter can also be used to wait the first command
byte's timeout;
3. In BURST mode, the follow-up command bytes can be written in the
interrupt context directly, so that it doesn't need to return to the
task context. Returning to the task context reduces the throughput of
the BURST mode and in the worst cases where the system workload is very
high, this leads to the hardware driven automatic BURST mode exit.
In order not to increase memory consumption, convert 'done' into 'flags'
to contain multiple indications:
1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition,
indicating the completion of the command transaction.
2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first
command byte. A new command can utilize this flag to compete for the
right of accessing the underlying hardware. There is a follow-up bug
fix that has utilized this new flag.
The 2 flags are important because it also reflects a key concept of IO
programs' design used in the system softwares. Normally an IO program
running in the kernel should first be implemented in the asynchronous way.
And the 2 flags are the most common way to implement its synchronous
operations on top of the asynchronous operations:
1. POLL: This flag can be used to block until the asynchronous operations
can happen.
2. COMPLETE: This flag can be used to block until the asynchronous
operations have completed.
By constructing code cleanly in this way, many difficult problems can be
solved smoothly.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: Barton Xu <tank.xuhan@gmail.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 66b42b78bc upstream.
The advance_transaction() will be invoked from the IRQ context GPE handler
and the task context ec_poll(). The handling of this function is locked so
that the EC state machine are ensured to be advanced sequentially.
But there is a problem. Before invoking advance_transaction(), EC_SC(R) is
read. Then for advance_transaction(), there could be race condition around
the lock from both contexts. The first one reading the register could fail
this race and when it passes the stale register value to the state machine
advancement code, the hardware condition is totally different from when
the register is read. And the hardware accesses determined from the wrong
hardware status can break the EC state machine. And there could be cases
that the functionalities of the platform firmware are seriously affected.
For example:
1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may
be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the
hardware will either refuse to respond a next EC_SC(W) write of the next
command or discard the current WR_EC command when it receives a EC_SC(W)
write of the next command.
2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the
EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write.
The next EC_DATA(R) could never be responded by the hardware. This is
the root cause of the reported issue.
Fix this issue by moving the EC_SC(R) access into the lock so that we can
ensure that the state machine is advanced consistently.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: Barton Xu <tank.xuhan@gmail.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 867f9d463b upstream.
The recently merged change (in v3.14-rc6) to ACPI resource detection
(below) causes all zero length ACPI resources to be elided from the
table:
commit b355cee88e
Author: Zhang Rui <rui.zhang@intel.com>
Date: Thu Feb 27 11:37:15 2014 +0800
ACPI / resources: ignore invalid ACPI device resources
This change has caused a regression in (at least) serial port detection
for a number of machines (see LP#1313981 [1]). These seem to represent
their IO regions (presumably incorrectly) as a zero length region.
Reverting the above commit restores these serial devices.
Only elide zero length resources which lie at address 0.
Fixes: b355cee88e (ACPI / resources: ignore invalid ACPI device resources)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e63f6e28dd upstream.
Revert commit ab0fd674d6 (ACPI / AC: Remove AC's proc directory.),
because some old tools (e.g. kpowersave from kde 3.5.10) are still
using /proc/acpi/ac_adapter.
Fixes: ab0fd674d6 (ACPI / AC: Remove AC's proc directory.)
Reported-and-tested-by: Sorin Manolache <sorinm@gmail.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
