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* w1: fix loop in w1_fini()Dan Carpenter2023-08-111-2/+2
| | | | | | | | | | | | | | | [ Upstream commit 83f3fcf96fcc7e5405b37d9424c7ef26bfa203f8 ] The __w1_remove_master_device() function calls: list_del(&dev->w1_master_entry); So presumably this can cause an endless loop. Fixes: 7785925dd8e0 ("[PATCH] w1: cleanups.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* w1: fix WARNING after calling w1_process()Yang Yingliang2023-02-061-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 36225a7c72e9e3e1ce4001b6ce72849f5c9a2d3b ] I got the following WARNING message while removing driver(ds2482): ------------[ cut here ]------------ do not call blocking ops when !TASK_RUNNING; state=1 set at [<000000002d50bfb6>] w1_process+0x9e/0x1d0 [wire] WARNING: CPU: 0 PID: 262 at kernel/sched/core.c:9817 __might_sleep+0x98/0xa0 CPU: 0 PID: 262 Comm: w1_bus_master1 Tainted: G N 6.1.0-rc3+ #307 RIP: 0010:__might_sleep+0x98/0xa0 Call Trace: exit_signals+0x6c/0x550 do_exit+0x2b4/0x17e0 kthread_exit+0x52/0x60 kthread+0x16d/0x1e0 ret_from_fork+0x1f/0x30 The state of task is set to TASK_INTERRUPTIBLE in loop in w1_process(), set it to TASK_RUNNING when it breaks out of the loop to avoid the warning. Fixes: 3c52e4e62789 ("W1: w1_process, block or sleep") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20221205101558.3599162-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* w1: fix deadloop in __w1_remove_master_device()Yang Yingliang2023-02-061-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 25d5648802f12ae486076ceca5d7ddf1fef792b2 ] I got a deadloop report while doing device(ds2482) add/remove test: [ 162.241881] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1. [ 163.272251] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1. [ 164.296157] w1_master_driver w1_bus_master1: Waiting for w1_bus_master1 to become free: refcnt=1. ... __w1_remove_master_device() can't return, because the dev->refcnt is not zero. w1_add_master_device() | w1_alloc_dev() | atomic_set(&dev->refcnt, 2) | kthread_run() | |__w1_remove_master_device() | kthread_stop() // KTHREAD_SHOULD_STOP is set, | // threadfn(w1_process) won't be | // called. | kthread() | | // refcnt will never be 0, it's deadloop. | while (atomic_read(&dev->refcnt)) {...} After calling w1_add_master_device(), w1_process() is not really invoked, before w1_process() starting, if kthread_stop() is called in __w1_remove_master_device(), w1_process() will never be called, the refcnt can not be decreased, then it causes deadloop in remove function because of non-zero refcnt. We need to make sure w1_process() is really started, so move the set refcnt into w1_process() to fix this problem. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20221205080434.3149205-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* w1: core: match sub-nodes of bus masters in devicetreeDaniel Mack2018-07-111-0/+3
| | | | | | | | | Once a new slave device is detected, match it against all sub-nodes of the master bus controller. If a match is found, set the slave device's of_node pointer. Signed-off-by: Daniel Mack <daniel@zonque.org> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
* 1wire: family module autoload fails because of upper/lower case mismatch.Ingo Flaschberger2018-05-141-1/+1
| | | | | | | | | | 1wire family module autoload fails because of upper/lower  case mismatch. Signed-off-by: Ingo Flaschberger <ingo.flaschberger@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: use put_device() if device_register() failArvind Yadav2018-03-141-0/+1
| | | | | | | | 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>
* drivers: w1: add hwmon support structuresJaghathiswari Rankappagounder Natarajan2017-08-311-1/+17
| | | | | | | | | | This patch has changes to w1.h/w1.c generic files to add (optional) hwmon support structures. Signed-off-by: Jaghathiswari Rankappagounder Natarajan <jaghu@google.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: w1: Add 1w slave driver for DS28E05 EEPROMAndrew Worsley2017-08-281-0/+2
| | | | | | | | | 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>
* w1: constify attribute_group structures.Arvind Yadav2017-08-281-1/+1
| | | | | | | | | 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>
* w1: Fix slave count on 1-Wire bus (resend)Alex A. Mihaylov2017-07-171-2/+2
| | | | | | | | | | | 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>
* w1: Add subsystem kernel public interfaceAndrew F. Davis2017-06-091-3/+3
| | | | | | | | | | | | | | | | | | | | 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>
* w1: Organize driver source to natural/common orderAndrew F. Davis2017-05-251-8/+10
| | | | | | | | | | | | | | | 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>
* w1: Remove unneeded use of assert() and remove w1_log.hAndrew F. Davis2017-04-081-1/+0
| | | | | | | | | | | 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>
* w1: Fixup source file headersAndrew F. Davis2017-01-251-7/+0
| | | | | | | | | | | 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>
* w1: don't leak refcount on slave attach failure in w1_attach_slave_device()Maciej S. Szmigiero2017-01-251-0/+1
| | | | | | | | | | | | | | 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: 9fcbbac5ded489 ("w1: process w1 netlink commands in w1_process thread") Cc: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: fix timeout_us parameter descriptionWei Yongjun2016-08-311-2/+2
| | | | | | | Fix 'timeout_us' parameter description. Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: silence an uninitialized variable warningDan Carpenter2016-05-011-1/+1
| | | | | | | | 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: w1_process() is not freezable kthreadJiri Kosina2016-02-111-1/+0
| | | | | | | | | 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>
* w1: introduce an ability to specify microseconds bus scanning intervalsDmitry Khromov2015-05-241-1/+16
| | | | | | | | | | 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>
* w1: support auto-load of w1_bq27000 module.NeilBrown2014-11-261-1/+1
| | | | | | | | | | | | | | | | | | | | 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>
* w1: use pr_* instead of printkFjodor Schelichow2014-06-191-6/+4
| | | | | | | | | | | | | | 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: do not unlock unheld list_mutex in __w1_remove_master_device()Alexey Khoroshilov2014-05-271-0/+2
| | | | | | | | | | | | | | | | | 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: avoid recursive device_addDavid Fries2014-04-161-26/+6
| | | | | | | | | | | | | | | | | | | | | | | __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 47eba33a0997fc7362a 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>
* w1: small type cleanup in sysfsDan Carpenter2014-02-151-2/+2
| | | | | | | | | | | | | 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>
* w1: format for DocBook and fixesDavid Fries2014-02-071-4/+26
| | | | | | | | | 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>
* w1: process w1 netlink commands in w1_process threadDavid Fries2014-02-071-52/+128
| | | | | | | | | | | 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>
* w1: new netlink commands, add/remove/list slavesDavid Fries2014-02-071-4/+2
| | | | | | | | | | | | | | | 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>
* w1: continue slave search where previous left offDavid Fries2014-02-071-3/+15
| | | | | | | | | 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: increase w1_max_slave_count, allow write accessDavid Fries2014-02-071-2/+28
| | | | | | | | | | | | | | 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>
* w1: Only wake up the search process if it is going to be searchingDavid Fries2014-02-071-1/+3
| | | | | | | | | 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>
* w1: fixup search to support abort from netlinkDavid Fries2014-02-071-2/+1
| | | | | | | | | | | | | | | | | | | | | Before 63706172f33 "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. 9d1817cab2f030 "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>
* drivers: w1: make w1_slave::flags long to avoid memory corruptionMichal Nazarewicz2013-11-131-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* w1 - call request_module with w1 master mutex unlockedHans-Frieder Vogt2013-10-071-0/+3
| | | | | | | | | | | | | 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>
* w1 - fix fops in w1_bus_notifyHans-Frieder Vogt2013-10-071-0/+3
| | | | | | | | | | | | | | 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>
* drivers/w1/w1.c: replace strict_strtol() with kstrtol()Jingoo Han2013-09-111-4/+8
| | | | | | | | | | 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>
* w1: add attribute groups to struct w1_family_opsGreg Kroah-Hartman2013-08-221-32/+41
| | | | | | | | | 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>
* w1: use default attribute groups for w1 slave devicesGreg Kroah-Hartman2013-08-221-27/+11
| | | | | | | | | 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: remove race with sysfs file creationGreg Kroah-Hartman2013-08-221-38/+73
| | | | | | | | | | 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>
* w1: add family based automatic module loadingAlexander Stein2013-06-031-0/+2
| | | | | | | | | 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>
* w1: fix oops when w1_search is called from netlink connectorMarcin Jurkowski2013-03-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Sat, Mar 02, 2013 at 10:45:10AM +0100, Sven Geggus wrote: > This is the bad commit I found doing git bisect: > 04f482faf50535229a5a5c8d629cf963899f857c is the first bad commit > commit 04f482faf50535229a5a5c8d629cf963899f857c > 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+
* w1: remove CONFIG_HOTPLUG ifdefsBill Pemberton2012-11-211-7/+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>
* W1: split master mutex to avoid deadlocks.NeilBrown2012-06-131-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Revert "w1: introduce a slave mutex for serializing IO"Greg Kroah-Hartman2012-06-131-1/+0
| | | | | | | | | | | | This reverts commit 59d4467be405316916a4087d5b02d99196eeef04. 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>
* w1: cleanup w1_ueventDevendra Naga2012-06-121-8/+6
| | | | | | | | | | | 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: introduce a slave mutex for serializing IONeilBrown2012-06-121-0/+1
| | | | | | | | | | | | | | | | | | | | 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>
* w1: fix slave driver registration error messageDmitry Artamonow2012-04-091-1/+1
| | | | | | | | | W1 core prints "Failed to register master driver" if error happens on registering SLAVE driver. Fix it. Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: add fast search for single slave busEvgeniy Polyakov2011-12-091-0/+10
| | | | | | | | | | | | 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>
* MAINTAINERS: Evgeniy has movedEvgeniy Polyakov2011-08-251-2/+2
| | | | | | Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic: use <linux/atomic.h>Arun Sharma2011-07-261-1/+1
| | | | | | | | | | | | | | 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>
* w1: have netlink search update kernel listDavid Fries2011-05-261-3/+9
| | | | | | | | | | | | 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>
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