If device_register() returned an error! Always use put_device()
to give up the reference initialized in device_register().
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a one wire driver for the DS28E05 one wire slave chip. This chip
requires OverDrive support to talk to it.
Signed-off-by: Andrew Worsley <amworsley@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
attribute_group are not supposed to change at runtime. All functions
working with attribute_group provided by <linux/sysfs.h> work with
const attribute_group. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1-Wire bus have very fast algorith for exchange with single slave
device. Fix incorrect count of slave devices on connect second slave
device. This case on slave device probe() step we need use generic
(multislave) functions for read/write device.
Signed-off-by: Alex A. Mihaylov <minimumlaw@rambler.ru>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Like other subsystems we should be able to define slave devices outside
of the w1 directory. To do this we move public facing interface
definitions to include/linux/w1.h and rename the internal definition
file to w1_internal.h.
As w1_family.h and w1_int.h contained almost entirely public
driver interface definitions we simply removed these files and
moved the remaining definitions into w1_internal.h.
With this we can now start to move slave devices out of w1/slaves and
into the subsystem based on the function they implement, again like
other drivers.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Structures and functions should be ordered such that forward declaration
use is minimized.
MODULE_* macros should immediately follow the structures and functions
upon which they act.
Remaining MODULE_* macros should be at the end of the file in
alphabetical order.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The only use of assert() is in matrox_w1.c and is used to check the input
to probe() from the PCI subsystem for NULL values, these are guaranteed
to be populated and no other PCI driver makes this check, remove this.
As this was the only definition in w1_log.h, remove this also.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove filename from file, this is not done anymore as it doesn't
add anything and usually is incorrect as filename change often.
Also shorten the GPL to the more common address-less version and
remove excess white-space.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Near the beginning of w1_attach_slave_device() we increment a w1 master
reference count.
Later, when we are going to exit this function without actually attaching
a slave device (due to failure of __w1_attach_slave_device()) we need to
decrement this reference count back.
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Cc: stable@vger.kernel.org
Fixes: 9fcbbac5de ("w1: process w1 netlink commands in w1_process thread")
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If kstrtoint() returns -ERANGE then "tmp" is uninitialized.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Evgeniy Polaykov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
w1_process() calls try_to_freeze(), but the thread doesn't mark itself
freezable through set_freezable(), so the try_to_freeze() call is useless.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some of 1-Wire devices commonly associated with physical access control
systems are attached/generate presence for as short as 100 ms - hence
the tens-to-hundreds milliseconds scan intervals are required.
Signed-off-by: Dmitry Khromov <dk@icelogic.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1/ change request_module call to zero-pad single digit
family numbers. This appears to be the intention of
the code, but not what it actually does.
This means that the alias created for W1_FAMILY_SMEM_01
might actually be useful.
2/ Define a family name for the BQ27000 battery charge monitor.
Unfortunately this is the same number as W1_FAMILY_SMEM_01
so if both a compiled on a system, one module might need to
be blacklisted.
3/ Add a MODULE_ALIAS for the bq27000.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces all calls to the "printk" function within the main "w1"
directory by calls to the appropriate "pr_*" function thus addressing
the following warning generated by the checkpatch script:
WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ...
then dev_err(dev, ... then pr_err(... to printk(KERN_ERR ...
Signed-off-by: Fjodor Schelichow <fjodor.schelichow@hotmail.com>
Signed-off-by: Roman Sommer <romsom2@yahoo.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
w1_process_callbacks() expects to be called with dev->list_mutex held,
but it is the fact only in w1_process(). __w1_remove_master_device()
calls w1_process_callbacks() after it releases list_mutex.
The patch fixes __w1_remove_master_device() to acquire list_mutex
for w1_process_callbacks().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: David Fries <david@fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: stable <stable@vger.kernel.org> # 3.15
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
__w1_attach_slave_device calls device_add which calls w1_bus_notify
which calls the w1_bq27000 slave driver, which calls
platform_device_add and device_add and deadlocks on getting
&(&priv->bus_notifier)->rwsem as it is still held in the previous
device_add. This avoids the problem by processing the family
add/remove outside of the slave device_add call.
Commit 47eba33a09 introduced this deadlock and added
a KOBJ_ADD, as the add was already reported in device_register two add
events were being sent. This change suppresses the device_register
add so that any slave device sysfs entries are setup before the add
goes out.
Belisko Marek reported this change fixed the deadlock he was seeing on
ARM device tree, while testing on my x86-64 system never saw the
deadlock.
Reported-by: Belisko Marek <marek.belisko@gmail.com>
Signed-off-by: David Fries <David@Fries.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On 64 bit systems, a large value for "long tmp" is truncated when
assigning to "int md->max_slave_count" so we still end up with a value
less than one despite the "tmp < 1" check.
This is more of a problem for static checkers than a real life issue,
but it's simple enough to fix.
Acked-by: David Fries <david@fries.net>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch the code documentation format style to DocBook format, enable
DocBook documentation generation, and fix some comments.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Netlink is a socket interface and is expected to be asynchronous.
Clients can now make w1 requests without blocking by making use of the
w1_master thread to process netlink commands which was previously only
used for doing an automatic bus search.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce new commands to add, remove, and list slave devices through
the netlink interface. This can be useful to skip the search on a
static network. They could previously only be added or removed
through automatic search or sysfs, and this allows a program to only
use netlink.
Only allocate memory when needed, so move kzalloc into w1_get_slaves
where it was used.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Search will detect at most max_slave_count devices per run, if there
are more pick up the next search where the previous left off.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
w1_max_slave_count is only used to abort the search early
or take a fast search (when 1), so there isn't any reason to not allow
it to be updated through sysfs. Memory is not allocated based on
the current value and 10 is a rather low base number, increasing to
64, and printing a message the first time the count is reached and
there were more devices to discover to let the user know why not
all the devices were found.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's valid to set the search count to 0 to stop searching, so don't
wake up the search thread to not search.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Before 63706172f3 "rework kthread_stop()" kthread_should_stop()
always returned false when called from a non-kthread task, after it
would oops as a non-kthread didn't have that structure and netlink was
calling search from a thread which wasn't a kthread. 9d1817cab2
"w1: fix oops when w1_search is called from netlink connector",
modified the code to avoid calling kthread_stop from a netlink thread.
Introduce a w1_master flag and bit W1_ABORT_SEARCH to identify abort
to cleanly support both kthread and netlink search abort. A search
can take seconds to run, so it is important to abort early if the
hardware is removed in the middle of a search.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Marcin Jurkowski <marcin1j@gmail.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Sven Geggus <lists@fuchsschwanzdomain.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On architectures where long is more then 32 bits, modifying a 32-bit field
with set_bit (and other atomic bit operations) may cause bytes following
the field to by modified.
Because the endianness of the bits within a field is the native endianness
of the CPU[1], on big-endian machines, bit number zero is in the last byte
of the field.
Therefore, `set_bit(0, ptr)' on a 64-bit big-endian machine is roughly
equivalent to `((char *)ptr)[7] |= 1', and since w1 driver uses a 32-bit
field for holding the flags, this causes bytes beyond the field to be
modified.
[1] From Documentation/atomic_ops.txt:
Native atomic bit operations are defined to operate on objects
aligned to the size of an "unsigned long" C data type, and are
least of that size. The endianness of the bits within each
"unsigned long" are the native endianness of the cpu.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
request_module for w1 slave modules needs to be called with the w1
master mutex unlocked. Because w1_attach_slave_device gets always(?)
called with mutex locked, we need to temporarily unlock the w1 master
mutex for the loading of the w1 slave module.
Signed-off by: Hans-Frieder Vogt <hfvogt@gmx.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: stable <stable@vger.kernel.org> # 3.11+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a check to make sure that fops are only called if they have
been defined by the slave module.
Without this check modules like w1_smem cause a NULL pointer dereference
bug.
Signed-off by: Hans-Frieder Vogt <hfvogt@gmx.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: stable <stable@vger.kernel.org> # 3.11+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The usage of strict_strtol() is not preferred, because strict_strtol() is
obsolete. Thus, kstrtol() should be used.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This lets w1 slave drivers declare an attribute group, and not have to
create/destroy sysfs files directly. All w1 slave drivers will be fixed
to use this field up in follow-on patches to this one.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As we have 2 sysfs files for the w1 slave devices, let the driver core
create / destroy them automatically by setting the default attribute
group for them, saving code and housekeeping logic.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
W1 slave sysfs files are created _after_ userspace is notified that the
device has been added to the system. Fix that race by moving the
creation/remove of the files to the bus notifier that is there for doing
this type of thing.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch allows the 1-wire bus to autoload the corresponding module
for each slave being attached.
This works similar to bluetooth protocols.
Signed-off-by: Alexander Stein <alexander.stein@informatik.tu-chemnitz.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On Sat, Mar 02, 2013 at 10:45:10AM +0100, Sven Geggus wrote:
> This is the bad commit I found doing git bisect:
> 04f482faf5 is the first bad commit
> commit 04f482faf5
> Author: Patrick McHardy <kaber@trash.net>
> Date: Mon Mar 28 08:39:36 2011 +0000
Good job. I was too lazy to bisect for bad commit;)
Reading the code I found problematic kthread_should_stop call from netlink
connector which causes the oops. After applying a patch, I've been testing
owfs+w1 setup for nearly two days and it seems to work very reliable (no
hangs, no memleaks etc).
More detailed description and possible fix is given below:
Function w1_search can be called from either kthread or netlink callback.
While the former works fine, the latter causes oops due to kthread_should_stop
invocation.
This patch adds a check if w1_search is serving netlink command, skipping
kthread_should_stop invocation if so.
Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Josh Boyer <jwboyer@gmail.com>
Tested-by: Sven Geggus <lists@fuchsschwanzdomain.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org> # 3.0+
Remove conditional code based on CONFIG_HOTPLUG being false. It's
always on now in preparation of it going away as an option.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'mutex' in struct w1_master is use for two very different
purposes.
Firstly it protects various data structures such as the list of all
slaves.
Secondly it protects the w1 buss against concurrent accesses.
This can lead to deadlocks when the ->probe code called while adding a
slave needs to talk on the bus, as is the case for power_supply
devices.
ds2780 and ds2781 drivers contain a work around to track which
process hold the lock simply to avoid this deadlock. bq27000 doesn't
have that work around and so deadlocks.
There are other possible deadlocks involving sysfs.
When removing a device the sysfs s_active lock is held, so the lock
that protects the slave list must take precedence over s_active.
However when access power_supply attributes via sysfs, the s_active
lock must take precedence over the lock that protects accesses to
the bus.
So to avoid deadlocks between w1 slaves and sysfs, these must be
two separate locks. Making them separate means that the work around
in ds2780 and ds2781 can be removed.
So this patch:
- adds a new mutex: "bus_mutex" which serialises access to the bus.
- takes in mutex in w1_search and ds1wm_search while they access
the bus for searching. The mutex is dropped before calling the
callback which adds the slave.
- changes all slaves to use bus_mutex instead of mutex to
protect access to the bus
- removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the
related code from drivers/power/ds278[01]_battery.c which
calls them.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 59d4467be4.
Turns out it was the wrong version, will apply the correct version after
this.
Reported-by: NeilBrown <neilb@suse.de>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There were some return statements around in the w1_uevent, used goto
to cleanup those return statements with the help of err variable,
and also removed a semi colon at the end of the w1_uevent's closing
brace.
Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
w1 devices need a mutex to serial IO. Most use master->mutex.
However that is used for other purposes and they can conflict.
In particular master->mutex is held while w1_attach_slave_device is
called.
For bq27000, this registers a 'powersupply' device which tries to read the
current status. The attempt to read will cause a deadlock on
master->mutex.
So create a new per-slave mutex and use that for serializing IO for
bq27000.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This enables a much more efficient way of device searching. It uses the
1-wire read-rom operation which allows the direct reading of the slave
address. BUT this works only with exactly one slave on the bus.
Signed-off-by: Hubert Feurstein <h.feurstein@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
index c374978..9761950 100644
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reorganize so the netlink connector one wire search command will update
the kernel list of detected slave devices. Otherwise, a newly detected
device is unusable because unless it's in the kernel list of known devices
any commands will result in ENODEV status.
Signed-off-by: David Fries <David@Fries.net>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The search/pullup/add/remove device attributes were 0666 which would allow
arbitrary users to affect the 1 wire bus. Change to 0664 to prevent that.
I found this patch in the Android tree, apparently this has never been
sent upstream so doing it now.
Signed-off-by: Brian Swetland <swetland@google.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Trivial patch which adds the __init/__exit macros to the module_init/
module_exit functions of
drivers/w1/w1.c
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Arvind Yadav