linux-stable.git/include/linux, branch v3.19.4

regulator: palmas: Correct TPS659038 register definition for REGEN2

2015-04-13T12:03:56+00:00

commit e03826d5045e81a66a4fad7be9a8ecdaeb7911cf upstream.

The register offset for REGEN2_CTRL in different for TPS659038 chip as when
compared with other Palmas family PMICs. In the case of TPS659038 the wrong
offset pointed to PLLEN_CTRL and was causing a hang. Correcting the same.

Signed-off-by: Keerthy 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

dm snapshot: suspend merging snapshot when doing exception handover

2015-04-13T12:03:55+00:00

commit 09ee96b21456883e108c3b00597bb37ec512151b upstream.

The "dm snapshot: suspend origin when doing exception handover" commit
fixed a exception store handover bug associated with pending exceptions
to the "snapshot-origin" target.

However, a similar problem exists in snapshot merging.  When snapshot
merging is in progress, we use the target "snapshot-merge" instead of
"snapshot-origin".  Consequently, during exception store handover, we
must find the snapshot-merge target and suspend its associated
mapped_device.

To avoid lockdep warnings, the target must be suspended and resumed
without holding _origins_lock.

Introduce a dm_hold() function that grabs a reference on a
mapped_device, but unlike dm_get(), it doesn't crash if the device has
the DMF_FREEING flag set, it returns an error in this case.

In snapshot_resume() we grab the reference to the origin device using
dm_hold() while holding _origins_lock (_origins_lock guarantees that the
device won't disappear).  Then we release _origins_lock, suspend the
device and grab _origins_lock again.

NOTE to stable@ people:
When backporting to kernels 3.18 and older, use dm_internal_suspend and
dm_internal_resume instead of dm_internal_suspend_fast and
dm_internal_resume_fast.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

workqueue: fix hang involving racing cancel[_delayed]_work_sync()'s for PREEMPT_NONE

2015-03-26T12:59:42+00:00

commit 8603e1b30027f943cc9c1eef2b291d42c3347af1 upstream.

cancel[_delayed]_work_sync() are implemented using
__cancel_work_timer() which grabs the PENDING bit using
try_to_grab_pending() and then flushes the work item with PENDING set
to prevent the on-going execution of the work item from requeueing
itself.

try_to_grab_pending() can always grab PENDING bit without blocking
except when someone else is doing the above flushing during
cancelation.  In that case, try_to_grab_pending() returns -ENOENT.  In
this case, __cancel_work_timer() currently invokes flush_work().  The
assumption is that the completion of the work item is what the other
canceling task would be waiting for too and thus waiting for the same
condition and retrying should allow forward progress without excessive
busy looping

Unfortunately, this doesn't work if preemption is disabled or the
latter task has real time priority.  Let's say task A just got woken
up from flush_work() by the completion of the target work item.  If,
before task A starts executing, task B gets scheduled and invokes
__cancel_work_timer() on the same work item, its try_to_grab_pending()
will return -ENOENT as the work item is still being canceled by task A
and flush_work() will also immediately return false as the work item
is no longer executing.  This puts task B in a busy loop possibly
preventing task A from executing and clearing the canceling state on
the work item leading to a hang.

task A			task B			worker

						executing work
__cancel_work_timer()
  try_to_grab_pending()
  set work CANCELING
  flush_work()
    block for work completion
						completion, wakes up A
			__cancel_work_timer()
			while (forever) {
			  try_to_grab_pending()
			    -ENOENT as work is being canceled
			  flush_work()
			    false as work is no longer executing
			}

This patch removes the possible hang by updating __cancel_work_timer()
to explicitly wait for clearing of CANCELING rather than invoking
flush_work() after try_to_grab_pending() fails with -ENOENT.

Link: http://lkml.kernel.org/g/20150206171156.GA8942@axis.com

v3: bit_waitqueue() can't be used for work items defined in vmalloc
    area.  Switched to custom wake function which matches the target
    work item and exclusive wait and wakeup.

v2: v1 used wake_up() on bit_waitqueue() which leads to NULL deref if
    the target bit waitqueue has wait_bit_queue's on it.  Use
    DEFINE_WAIT_BIT() and __wake_up_bit() instead.  Reported by Tomeu
    Vizoso.

Signed-off-by: Tejun Heo 
Reported-by: Rabin Vincent 
Cc: Tomeu Vizoso 
Tested-by: Jesper Nilsson 
Tested-by: Rabin Vincent 
Signed-off-by: Greg Kroah-Hartman

serial: core: Fix iotype userspace breakage

2015-03-26T12:59:39+00:00

commit 2bb785169e9709d41220e5c18b0270883a82f85c upstream.

commit 3ffb1a8193bea ("serial: core: Add big-endian iotype")
re-numbered userspace-dependent values; ioctl(TIOCSSERIAL) can
assign the port iotype (which is expected to match the selected
i/o accessors), so iotype values must not be changed.

Cc: Kevin Cernekee 
Signed-off-by: Peter Hurley 
Reviewed-by: Kevin Cernekee 
Signed-off-by: Greg Kroah-Hartman

Revert "USB: serial: make bulk_out_size a lower limit"

2015-03-18T13:11:00+00:00

commit bc4b1f486fe69b86769e07c8edce472327a8462b upstream.

This reverts commit 5083fd7bdfe6760577235a724cf6dccae13652c2.

A bulk-out size smaller than the end-point size is indeed valid. The
offending commit broke the usb-debug driver for EHCI debug devices,
which use 8-byte buffers.

Fixes: 5083fd7bdfe6 ("USB: serial: make bulk_out_size a lower limit")
Reported-by: "Li, Elvin" 
Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman

quota: Store maximum space limit in bytes

2015-03-06T22:57:43+00:00

commit b10a08194c2b615955dfab2300331a90ae9344c7 upstream.

Currently maximum space limit quota format supports is in blocks however
since we store space limits in bytes, this is somewhat confusing. So
store the maximum limit in bytes as well. Also rename the field to match
the new unit and related inode field to match the new naming scheme.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

kernel: make READ_ONCE() valid on const arguments

2015-03-06T22:57:42+00:00

commit dd36929720f40f17685e841ae0d4c581c165ea60 upstream.

The use of READ_ONCE() causes lots of warnings witht he pending paravirt
spinlock fixes, because those ends up having passing a member to a
'const' structure to READ_ONCE().

There should certainly be nothing wrong with using READ_ONCE() with a
const source, but the helper function __read_once_size() would cause
warnings because it would drop the 'const' qualifier, but also because
the destination would be marked 'const' too due to the use of 'typeof'.

Use a union of types in READ_ONCE() to avoid this issue.

Also make sure to use parenthesis around the macro arguments to avoid
possible operator precedence issues.

Tested-by: Ingo Molnar 
Cc: Christian Borntraeger 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

kernel: Fix sparse warning for ACCESS_ONCE

2015-03-06T22:57:42+00:00

commit c5b19946eb76c67566aae6a84bf2b10ad59295ea upstream.

Commit 927609d622a3 ("kernel: tighten rules for ACCESS ONCE") results in
sparse warnings like "Using plain integer as NULL pointer" - Let's add a
type cast to the dummy assignment.
To avoid warnings lik "sparse: warning: cast to restricted __hc32" we also
use __force on that cast.

Fixes: 927609d622a3 ("kernel: tighten rules for ACCESS ONCE")
Signed-off-by: Christian Borntraeger 
Signed-off-by: Greg Kroah-Hartman

kernel: tighten rules for ACCESS ONCE

2015-03-06T22:57:42+00:00

commit 927609d622a3773995f84bc03b4564f873cf0e22 upstream.

Now that all non-scalar users of ACCESS_ONCE have been converted
to READ_ONCE or ASSIGN once, lets tighten ACCESS_ONCE to only
work on scalar types.
This variant was proposed by Alexei Starovoitov.

Signed-off-by: Christian Borntraeger 
Reviewed-by: Paul E. McKenney 
Signed-off-by: Greg Kroah-Hartman

kdb: Avoid printing KERN_ levels to consoles

2015-03-06T22:57:36+00:00

commit f7d4ca8bbfda23b4f1eae9b6757ff64166b093d5 upstream.

Currently when kdb traps printk messages then the raw log level prefix
(consisting of '\001' followed by a numeral) does not get stripped off
before the message is issued to the various I/O handlers supported by
kdb. This causes annoying visual noise as well as causing problems
grepping for ^. It is also a change of behaviour compared to normal usage
of printk() usage. For example -h ends up with different output to
that of kdb's "sr h".

This patch addresses the problem by stripping log levels from messages
before they are issued to the I/O handlers. printk() which can also
act as an i/o handler in some cases is special cased; if the caller
provided a log level then the prefix will be preserved when sent to
printk().

The addition of non-printable characters to the output of kdb commands is a
regression, albeit and extremely elderly one, introduced by commit
04d2c8c83d0e ("printk: convert the format for KERN_ to a 2 byte
pattern"). Note also that this patch does *not* restore the original
behaviour from v3.5. Instead it makes printk() from within a kdb command
display the message without any prefix (i.e. like printk() normally does).

Signed-off-by: Daniel Thompson 
Cc: Joe Perches 
Signed-off-by: Jason Wessel 
Signed-off-by: Greg Kroah-Hartman