As with the ETMv3.x driver, calling 'smp_call_function_single()'
twice in a row is highly ineffective. As such moving function
'etm4_os_unlock()' before the default initialisation takes
place, which results in the same outcome.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 66bbbb77540e846b9aac4c9467aca936128951bf)
Splitting and updating the default initialisation for each etmv4
configuration so that it can be called at the beginning of each
session rather than initialisation time only.
Since the trace ID isn't expected to change with every session,
moving it with the default tracer initialisation.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit fc208abef39279903887bea955139f64bf0bbb12)
Similar to what was done on etm3x, splitting driver structure
etmv4_drvdata in two. One half is concerned with the HW
characteristics that are generally static in nature. The other
half deals with user configuration and will change from one
trace session to another.
No gain/loss of functionality is incurred from this patch.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 54ff892b76c68ea3fa0ba53a0cdc4508b35aee6f)
Adding new sysFS management interface to query the configuration
and the traceid registers. Both are required to convey information
to the perf cmd line tools when using ETMv4 tracers as PMU.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 7c38aa4b03b3fc6ce17e5a00327f8c0be18daf8a)
As with the etm3x driver, sysFS entries are big enough to justify
their own file. As such moving all sysFS related declarations to
a dedicated location.
No gain/loss of functionality is incurred from this patch.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit a77de2637c9eb4794c6234b40cee2a243c548875)
Some STM devices adjust software assigned master numbers depending on
the trace source and its runtime state and whatnot. This patch adds
a sysfs attribute to inform the trace-side software that master numbers
assigned to software sources will not match those in the STP stream,
so that, for example, master/channel allocation policy can be adjusted
accordingly.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 8e996a2874bbbed30e8dfe881453825fc6b7654e)
Readability: a postfix increment is used on a pointer which is not
used anywhere afterwards, which may send the reader looking through
the function one extra time. Drop the unnecessary increment.
Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
(cherry picked from commit fb0801904bbbc7b109d4009520c7fa34bcfb7450)
Currently, stm_register_device() makes the device visible and then
proceeds to initializing spinlocks and other properties, which leaves
a window when the device can already be opened but is not yet fully
operational.
Fix this by reversing the initialization order.
Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
(cherry picked from commit 389b6699a2aa0b457aa69986e9ddf39f3b4030fd)
Currently, the error path of stm_register_device() forgets to unregister
the chrdev. Fix this.
Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
(cherry picked from commit cbe4a61d1ddc4790d950ca8c33ef79ee68ef5e2b)
No point in explicitly setting something to zero right after we
explicitly checked that it is zero. Fix this.
Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
(cherry picked from commit 8fa11d1c1322f3de40a0e3f3f3e57436a204fcc4)
Changing nr_devs after the module has been loaded doesn't actually
change anything, so just make it read-only.
Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
(cherry picked from commit c8be4899449c0b27bc5daf71742cd601b2b3b4e3)
Changing nr_dummies after the module has been loaded doesn't actually
change anything, so just make it read-only.
Reported-by: Alan Cox <alan.cox@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
(cherry picked from commit 118b4515aa6916ee7751f29c8b2a3af95abc9783)
In commit 941943cf519f7cacbbcecee5c4ef4b77b466bd5c ("drivers/hwtracing:
make coresight-* explicitly non-modular") we removed all uses of
modular functions/macros in favour of their built-in equivlents in
this subsystem.
However that commit and commit 0bcbf2e30ff2271b54f54c8697a185f7d86ec6e4
("coresight: etm-perf: new PMU driver for ETM tracers") were in flight
at the same time, and hence one new non-modular user of module_init
crept back in. Fix it up like we did all the others.
Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ca48fa22c3ed3b7b062bc6fa7b72493c00571e33)
None of the Kconfig currently controlling compilation of any of
the files here are tristate, meaning that none of it currently
is being built as a module by anyone.
We need not be concerned about .remove functions and blocking the
unbind sysfs operations, since that was already done in a recent
commit.
Lets remove any remaining modular references, so that when reading the
drivers there is no doubt they are builtin-only.
All drivers get mostly the same changes, so they are handled in batch.
Changes are (1) convert to builtin_amba_driver, (2) delete module.h
include where unused, and (3) relocate the description into the
comments so we don't need MODULE_DESCRIPTION and associated tags.
The etm3x and etm4x use module_param_named, and have been adjusted
to just include moduleparam.h for that purpose.
In commit f309d44431 ("platform_device:
better support builtin boilerplate avoidance") we introduced the
builtin_driver macro.
Here we use that support and extend it to amba driver registration,
so where a driver is clearly non-modular and builtin-only, we can
update with the simple mapping of
module_amba_driver(...) ---> builtin_amba_driver(...)
Since module_amba_driver() uses the same init level priority as
builtin_amba_driver() the init ordering remains unchanged with
this commit.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 941943cf519f7cacbbcecee5c4ef4b77b466bd5c)
TraceID values have to be unique for all tracers and
consistent between drivers and user space. As such
introducing a central function to be used whenever a
traceID value is required.
The patch also account for data traceIDs, which are usually
I(N) + 1.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 17534ceb835a1a96eb921a2a80df168723d6570a)
Perf is a well known and used tool for performance monitoring
and much more. A such it is an ideal candidate for integration
with coresight based HW tracing.
This patch introduces a PMU that represent a coresight tracer to
the Perf core.
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 0bcbf2e30ff2271b54f54c8697a185f7d86ec6e4)
Adding an ETB10 specific AUX area operations to be used
by the perf framework when events are initialised.
Part of this operation involves modeling the mmap'ed area
based on the specific ways a sink buffer gathers information.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 2997aa4063d97fdb39450c6078bd81a7b0504f22)
Adding an operation mode to the sink->enable() API in order
to prevent simultaneous access from different callers.
TPIU and TMC won't be supplemented with the AUX area
API immediately and as such ignore the new mode.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit e827d4550aa3225b8965ce4c266208cfe0297509)
Moving to use local atomic operations to take advantage of the
lockless implementation, something that will come handy when
the ETB is accessed from the Perf subsystem. Also changing the
name of the variable to something more meaningful.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 27b10da8fff27d74b755707e61637f6ab488c617)
That way traces can be enabled and disabled automatically
from the Perf subystem using the PMU abstraction.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 882d5e112491c875ab7c8c336b8beaeec54d0509)
Adding new mode to limit tracing to kernel or user space.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 2127154d115d4fe8f18300e5ef6f566581359d56)
There is really no point in having two functions to take care
of doing the initial tracer configuration. As such moving
everything to 'etm_set_default()'.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c528a25ac7c4dacba9e4d98d5f06846939c5966f)
Changing default configuration to include the entire address
range rather than just the kernel. That way traces are more
inclusive and it is easier to narrow down if needed.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit e19217299caf1a54c55081ab6339b3baccec63b0)
There is no need to use the event enable's "always false" event to
stop trace collection. For that purpose setting the programming bit
(ETMCR:10) is enough.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 47cd066cd00a65902ee3bd57da5bd395cb83aff9)
Adding a new mode to source API enable() in order to
distinguish where the request comes from. That way it is
possible to perform different operations based on where
the request was issued from.
The ETM4x driver is also modified to keep in sync with the
new interface.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 22fd532eaa0c24d86e23d8e9e3b7feac4a8cac80)
Splitting "etm_drvdata" in two sections, one for the HW specific
data and another for user configuration.
That way it is easier to manipulate and zero out the configuration
data when more than one concurrent tracing session configuration
is active.
Also taking care of up-lifting all the code affected by this new
arrangement. No loss or gain of functionality (other than what is
mentioned above) is introduced by this patch.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 1925a470ce69cdfa2b82ac1565d58dfd39cd877d)
Calling function 'smp_call_function_single()' to unlock a
tracer and calling it again right after to perform the
default initialisation doesn't make sense.
Moving 'etm_os_unlock()' just before making the default
initialisation results in the same outcome while saving
one call to 'smp_call_function_single()'.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ae69a1da399fccaed406932f5cbee55a6f9d4425)
SysFS entries are big enough to justify their own file.
As such moving all sysFS related declarations to a dedicated
location.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c04148e708c0d8d7eabc447946b712a66b468b47)
Moving functions etm_readl/writel to file "coresight-etm.h"
so that the main ETM3x driver can be split in more than one
file.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c1f8e57c9e6692f6e8c6c1f9eab7a46264ac4245)
Moving PM runtime operations in Coresight devices enable() and
disable() API to the framework core when a path is setup. That
way the runtime core doesn't have to be involved everytime a
path is enabled. It also avoids calling runtime PM operations
in IRQ context.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 5da5325fa85658ee793792b5285dd5fdb76ccfb7)
Add an API allowing external code to quickly get a handle on the
sink within a path. The sink is always last, but adding an API allows
to keep the path's node structure private and remove redundant checks.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b6404e21f023e4aa208a0ba03d55a9c8a57cb940)
When using the Coresight framework from the sysFS interface a
tracer is always handling a single session and as such, a path
can be associated with a tracer. But when supporting multiple
session per tracer there is no guarantee that sessions will always
have the same path from source to sink.
This patch is removing the automatic association between path and
tracers. The building of a path and enablement of the components
in the path are decoupled, allowing for the association of a path
with a session rather than a tracer.
To keep backward functionality with the current sysFS access methods
a per-cpu place holder is used to keep a handle on the path built when
tracers are enabled. Lastly APIs to build paths and enable tracers are
made public so that other subsystem can interact with the Coresight
framework.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b3e94405941e6916d5e365454d74560c2bea47ca)
The dma_alloc_coherent return an "void *" not an "void __iomen *".
It uses the wrong parameters when calls dma_free_coherent function.
The sparse tool output logs as the following:
coresight-tmc.c:199:23: expected void *<noident>
coresight-tmc.c:199:23: got void [noderef] <asn:2>*vaddr
coresight-tmc.c:336:30: warning: incorrect type in assignment
(different address spaces)
coresight-tmc.c:336:30: expected char *buf
coresight-tmc.c:336:30: got void [noderef] <asn:2>*
coresight-tmc.c:769:50: warning: incorrect type in argument 4
(different base types)
coresight-tmc.c:769:50: expected unsigned long long
[unsigned] [usertype] dma_handle
coresight-tmc.c:769:50: got restricted gfp_t
Signed-off-by: Eric Long <eric.long@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 61390593f72377c3a8f41ef998462e2d3985adac)
"DEVICE_ATTR_RO(name)" should be defined as static. And
there is an unnecessary space at the front of the code.
The sparse tool output logs as the following:
coresight-etm4x.c:2224:1: warning: symbol 'dev_attr_trcoslsr' was
not declared. Should it be static?
coresight-etm4x.c:2225:1: warning: symbol 'dev_attr_trcpdcr' was
not declared. Should it be static?
coresight-etm4x.c:2226:1: warning: symbol 'dev_attr_trcpdsr' was
not declared. Should it be static?
And the smatch tool output logs as the following:
of_coresight.c:89 of_coresight_alloc_memory() warn:
inconsistent indenting
Signed-off-by: Eric Long <eric.long@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit bf16e5b8cdeabc1fe6565af0be475bb2084dc388)
Other than plainly parsing the device tree there is no way to
know which CPU a tracer is affined to. As such adding an
interface to lookup the CPU field enclosed in the etm_drvdata
structure that was initialised at boot time.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 52210c8745e418f82f3f0aeeee01d7bc4858812a)
The coresight drivers have absolutely no control over bind and unbind
operations triggered from sysfs. The operations simply can't be
cancelled or denied event when one or several tracing sessions are
under way. Since the memory associated to individual device is
invariably freed, the end result is a kernel crash when the path from
source to sink is travelled again as demonstrated here[1].
One solution could be to keep track of all the path (i.e tracing
session) that get created and iterate through the elements of those path
looking for the coresight device that is being removed. This proposition
doesn't scale well since there is no upper bound on the amount of
concurrent trace session that can be created.
With the above in mind, this patch prevent devices from being unbounded
from their driver by using the driver->suppress_bind_attr option. That way
trace sessions can be managed without fearing to loose devices.
Since device can't be removed anymore the xyz_remove() functions found in
each driver is also removed.
[1]. http://www.spinics.net/lists/arm-kernel/msg474952.html
Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b15f0fb657e040401d875d11ae13b269af8a16e0)
In function 'coresight_unregister()', all references to the csdev that
is being taken away need to be removed from the topology. Otherwise
building the next coresight path from source to sink may use memory
that has been released.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ad725aee070caf8fa93d84d6fb78321f9642db18)
The reference count taken by function bus_find_device() needs
to be released if a child device is found, something this patch
is adding.
Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit f2dfab3568fc32afeac8b698481e80e7ab2dc658)
In its current form the code never frees csdev->refcnt allocated
in coresight_register(). There is also a problem with csdev->conns
that is freed before device_unregister() rather than in the device
release function.
This patch addresses both issues by moving kfree(csdev->conns) to
coresight_device_release() and freeing csdev->refcnt, also in
the same function.
Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit fae54158792aec705620bdc3938d342879204f0c)
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b9884d3b79f60846cdf04be262d13bca8996f99a)
Connection child names associated to ports can sometimes be NULL,
which is the case when booting a system on QEMU or when the Coresight
power domain isn't switched on.
This patch is adding a check to make sure a NULL string isn't fed
to strcmp(), something that avoid crashing the system.
Cc: <stable@vger.kernel.org> # v3.18+
Reported-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit fadf3a44e974b030e7145218ad1ab25e3ef91738)
STM device's link callback has the power to abort master/channel
assignment by returning a negative error code. Use this in dummy
stm device to optionally abort assigning certain channel IDs.
This is useful as fault injection into the stm class core, for
testing purposes.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit adcde635f5d6b77e9f11087af09c6f62da2bf108)
STM device's unlink callback is never actually called from anywhere in
the stm class code.
This patch adds calls to stm driver's unlink method after the unlinking
has succeeded.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit cc8424074e51355e0c6ba717d8edc50d408f2802)
There is a window in stm_source_link_drop(), during which the source's
link may change before locks are acquired. When this happens, it throws
a warning, since this is not an expected scenario.
This patch handles the race in such a way that if the link appears to
have changed by the time we took the locks, it will release them and
repeat the whole unlinking procedure from the beginning, unless the
other contender beat us to it.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b4ca34aaf78ed0cdfc15956d377064104257a437)
STM code takes references to the stm device and its module for the
duration of the character device's existence or the stm_source link.
Dropping these references is not well balanced everywhere, which may
lead to leaks.
This patch balances the acquisition and releasing of these two
references and annotates each site so that it's easier to verify
correctness by reading the code.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit f7c81c7176c72c7899390754b4b038a64b296e4d)
It is possible to concurrently assign the same output (a character
device writer or an stm_source device) to different stm devices,
which sets off a strategically placed warning in stm_output_assign().
To avoid this, use a spinlock to serialize (un)assignments between
outputs and stm devices.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit cde4ad8368840e414ecf67db258fe1dabaa5fd2e)
If an illegal attempt is made to unlink stm source device from an
stm device, the stm device's link spinlock mistakenly remains locked.
While this really shouldn't happen (there's a warning in place), the
locking should remain in order so that we can still recover from this
situation if it indeed does happen.
This patch unifies the unlocking in the exit path of
__stm_source_link_drop() to fix this.
Reported-by: Laurent Fert <laurent.fert@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 1810f2c44817c74ca3d05d1e3981e3a2e2ceb6f5)
Heartbeat stm source may have multiple instances (for connecting to
different stm devices). Each instance will send a periodic test message
over its stm device when it is linked. This can be used for testing stm
class framework, stm device drivers or as a heartbeat over the stm link.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 1192918530381b5cfc0e5da51233fa94f783b221)
