ACPICA uses acpi_hw_write_gpe_enable_reg() to re-enable a GPE after
an event signaled by it has been handled. However, this function
writes the entire GPE enable mask to the GPE's enable register which
may not be correct. Namely, if one of the other GPEs in the same
register was previously enabled by acpi_enable_gpe() and subsequently
disabled using acpi_set_gpe(), acpi_hw_write_gpe_enable_reg() will
re-enable it along with the target GPE.
To fix this issue rework acpi_hw_write_gpe_enable_reg() so that it
calls acpi_hw_low_set_gpe() with a special action value,
ACPI_GPE_COND_ENABLE, that will make it only enable the GPE if the
corresponding bit in its register's enable_for_run mask is set.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPICA uses acpi_ev_enable_gpe() for enabling GPEs at the low level,
which is incorrect, because this function only enables the GPE if the
corresponding bit in its enable register's enable_for_run mask is set.
This causes acpi_set_gpe() to work incorrectly if used for enabling
GPEs that were not previously enabled with acpi_enable_gpe(). As a
result, among other things, wakeup-only GPEs are never enabled by
acpi_enable_wakeup_device(), so the devices that use them are unable
to wake up the system.
To fix this issue remove acpi_ev_enable_gpe() and its counterpart
acpi_ev_disable_gpe() and replace acpi_hw_low_disable_gpe() with
acpi_hw_low_set_gpe() that will be used instead to manipulate GPE
enable bits at the low level. Make the users of acpi_ev_enable_gpe()
and acpi_ev_disable_gpe() call acpi_hw_low_set_gpe() instead and
make sure that GPE enable masks are only updated by acpi_enable_gpe()
and acpi_disable_gpe() when GPE reference counters change from 0
to 1 and from 1 to 0, respectively.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
We have ported Rafael's major GPE changes
(ACPI: Use GPE reference counting to support shared GPEs) into ACPICA code base.
But the port and Rafael's original patch have some differences, so we made
below patch to make linux GPE code consistent with ACPICA code base.
Most changes are about comments and coding styles.
Other noticeable changes are based on:
Rafael: Reduce code duplication related to GPE lookup
https://patchwork.kernel.org/patch/86237/
Rafael: Always use the same lock for GPE locking
https://patchwork.kernel.org/patch/90471/
A new field gpe_count in struct acpi_gpe_block_info to record the number
of individual GPEs in block.
Rename acpi_ev_save_method_info to acpi_ev_match_gpe_method.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Robert Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This change will enable debug object output via a global variable,
acpi_gbl_enable_aml_debug_object. This will help with remote machine
debugging. Also, moved all debug object support code to a new
file, exdebug.c. Entire debug object module can now be
configured out of the ACPICA build if desired.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: Make RCU lockdep check the lockdep_recursion variable
rcu: Update docs for rcu_access_pointer and rcu_dereference_protected
rcu: Better explain the condition parameter of rcu_dereference_check()
rcu: Add rcu_access_pointer and rcu_dereference_protected
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/radeon/kms: add FireMV 2400 PCI ID.
drm/radeon/kms: allow R500 regs VAP_ALT_NUM_VERTICES and VAP_INDEX_OFFSET
drivers/gpu/radeon: Add MSPOS regs to safe list.
drm/radeon/kms: disable the tv encoder when tv/cv is not in use
drm/radeon/kms: adjust pll settings for tv
drm/radeon/kms: fix tv dac conflict resolver
drm/radeon/kms/evergreen: don't enable hdmi audio stuff
drm/radeon/kms/atom: fix dual-link DVI on DCE3.2/4.0
drm/radeon/kms: fix rs600 tlb flush
drm/radeon/kms: print GPU family and device id when loading
drm/radeon/kms: fix calculation of mipmapped 3D texture sizes
drm/radeon/kms: only change mode when coherent value changes.
drm/radeon/kms: more atom parser fixes (v2)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: wacom - switch mode upon system resume
Revert "Input: wacom - merge out and in prox events"
Input: matrix_keypad - allow platform to disable key autorepeat
Input: ALPS - add signature for HP Pavilion dm3 laptops
Input: i8042 - spelling fix
Input: sparse-keymap - implement safer freeing of the keymap
Input: update the status of the Multitouch X driver project
Input: clarify the no-finger event in multitouch protocol
Input: bcm5974 - retract efi-broken suspend_resume
Input: sparse-keymap - free the right keymap on error
Among else, this allows projects like libdc1394 to carry copies of the
ABI related header files without them or distributors having to worry
about effects on the project's overall license terms. Switch to MIT
license as suggested by Kristian. Also update the year in the
copyright statement according to source history.
Cc: Jay Fenlason <fenlason@redhat.com>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
This patch adds variants of rcu_dereference() that handle
situations where the RCU-protected data structure cannot change,
perhaps due to our holding the update-side lock, or where the
RCU-protected pointer is only to be fetched, not dereferenced.
These are needed due to some performance concerns with using
rcu_dereference() where it is not required, aside from the need
for lockdep/sparse checking.
The new rcu_access_pointer() primitive is for the case where the
pointer is be fetch and not dereferenced. This primitive may be
used without protection, RCU or otherwise, due to the fact that
it uses ACCESS_ONCE().
The new rcu_dereference_protected() primitive is for the case
where updates are prevented, for example, due to holding the
update-side lock. This primitive does neither ACCESS_ONCE() nor
smp_read_barrier_depends(), so can only be used when updates are
somehow prevented.
Suggested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: eric.dumazet@gmail.com
LKML-Reference: <1270852752-25278-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFSv4: fix delegated locking
NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptible
NFS: Fix a race with the new commit code
NFS: Ensure that writeback_single_inode() calls write_inode() when syncing
NFS: Fix the mode calculation in nfs_find_open_context
NFSv4: Fall back to ordinary lookup if nfs4_atomic_open() returns EISDIR
Arnaud Giersch reports that NFSv4 locking is broken when we hold a
delegation since commit 8e469ebd6d (NFSv4:
Don't allow posix locking against servers that don't support it).
According to Arnaud, the lock succeeds the first time he opens the file
(since we cannot do a delegated open) but then fails after we start using
delegated opens.
The following patch fixes it by ensuring that locking behaviour is
governed by a per-filesystem capability flag that is initially set, but
gets cleared if the server ever returns an OPEN without the
NFS4_OPEN_RESULT_LOCKTYPE_POSIX flag being set.
Reported-by: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits)
cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch
loop: Update mtime when writing using aops
block: expose the statistics in blkio.time and blkio.sectors for the root cgroup
backing-dev: Handle class_create() failure
Block: Fix block/elevator.c elevator_get() off-by-one error
drbd: lc_element_by_index() never returns NULL
cciss: unlock on error path
cfq-iosched: Do not merge queues of BE and IDLE classes
cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging
i2o: Remove the dangerous kobj_to_i2o_device macro
block: remove 16 bytes of padding from struct request on 64bits
cfq-iosched: fix a kbuild regression
block: make CONFIG_BLK_CGROUP visible
Remove GENHD_FL_DRIVERFS
block: Export max number of segments and max segment size in sysfs
block: Finalize conversion of block limits functions
block: Fix overrun in lcm() and move it to lib
vfs: improve writeback_inodes_wb()
paride: fix off-by-one test
drbd: fix al-to-on-disk-bitmap for 4k logical_block_size
...
radix_tree_tag_get() is not safe to use concurrently with radix_tree_tag_set()
or radix_tree_tag_clear(). The problem is that the double tag_get() in
radix_tree_tag_get():
if (!tag_get(node, tag, offset))
saw_unset_tag = 1;
if (height == 1) {
int ret = tag_get(node, tag, offset);
may see the value change due to the action of set/clear. RCU is no protection
against this as no pointers are being changed, no nodes are being replaced
according to a COW protocol - set/clear alter the node directly.
The documentation in linux/radix-tree.h, however, says that
radix_tree_tag_get() is an exception to the rule that "any function modifying
the tree or tags (...) must exclude other modifications, and exclude any
functions reading the tree".
The problem is that the next statement in radix_tree_tag_get() checks that the
tag doesn't vary over time:
BUG_ON(ret && saw_unset_tag);
This has been seen happening in FS-Cache:
https://www.redhat.com/archives/linux-cachefs/2010-April/msg00013.html
To this end, remove the BUG_ON() from radix_tree_tag_get() and note in various
comments that the value of the tag may change whilst the RCU read lock is held,
and thus that the return value of radix_tree_tag_get() may not be relied upon
unless radix_tree_tag_set/clear() and radix_tree_delete() are excluded from
running concurrently with it.
Reported-by: Romain DEGEZ <romain.degez@smartjog.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most drives from Seagate, Hitachi, and possibly other brands,
do not allow LBA28 access to sector number 0x0fffffff (2^28 - 1).
So instead use LBA48 for such accesses.
This bug could bite a lot of systems, especially when the user has
taken care to align partitions to 4KB boundaries. On misaligned systems,
it is less likely to be encountered, since a 4KB read would end at
0x10000000 rather than at 0x0fffffff.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
