linux-toradex.git/drivers/edac/edac_device.c, branch v2.6.30-rc5

edac: use to_delayed_work()

2009-04-13T22:04:34+00:00

The edac-core driver includes code which assumes that the work_struct
which is included in every delayed_work is the first member of that
structure.  This is currently the case but might change in the future, so
use to_delayed_work() instead, which doesn't make such an assumption.

linux-2.6.30-rc1 has the to_delayed_work() function that will allow this
patch to work

Signed-off-by: Jean Delvare 
Signed-off-by: Doug Thompson 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

edac: struct device: replace bus_id with dev_name(), dev_set_name()

2009-01-06T23:59:30+00:00

This patch is part of a larger patch series which will remove the "char
bus_id[20]" name string from struct device.  The device name is managed in
the kobject anyway, and without any size limitation, and just needlessly
copied into "struct device".

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Greg Kroah-Hartman 
Acked-by: Doug Thompson 
Signed-off-by: Kay Sievers 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

edac: fix edac core deadlock when removing a device

2008-12-23T23:58:21+00:00

When deleting an edac device, we have to wait for its edac_dev.work to be
completed before deleting the whole edac_dev structure.  Since we have no
idea which work in current edac_poller's workqueue is the work we are
conerned about, we wait for all work in the edac_poller's workqueue to be
proceseed.  This is done via flush_cpu_workqueue() which inserts a
wq_barrier into the tail of the workqueue and then sleeping on the
completion of this wq_barrier.  The edac_poller will wake up sleepers when
it is found.

EDAC core creates only one kernel worker thread, edac_poller, to run the
works of all current edac devices.  They share the same callback function
of edac_device_workq_function(), which would grab the mutex of
device_ctls_mutex first before it checks the device.  This is exactly
where edac_poller and rmmod would have a great chance to deadlock.

In below call trace of rmmod > ... >
edac_device_del_device >
edac_device_workq_teardown > flush_workqueue > flush_cpu_workqueue,

device_ctls_mutex would have already been grabbed by
edac_device_del_device().  So, on one hand rmmod would sleep on the
completion of a wq_barrier, holding device_ctls_mutex; on the other hand
edac_poller would be blocked on the same mutex when it's running any one
of works of existing edac evices(Note, this edac_dev.work is likely to be
totally irrelevant to the one that is being removed right now)and never
would have a chance to run the work of above wq_barrier to wake rmmod up.

edac_device_workq_teardown() should not be called within the critical
region of device_ctls_mutex.  Just like is done in edac_pci_del_device()
and edac_mc_del_mc(), where edac_pci_workq_teardown() and
edac_mc_workq_teardown() are called after related mutex are released.

Moreover, an edac_dev.work should check first if it is being removed.  If
this is the case, then it should bail out immediately.  Since not all of
existing edac devices are to be removed, this "shutting flag" should be
contained to edac device being removed.  The current edac_dev.op_state can
be used to serve this purpose.

The original deadlock problem and the solution have been witnessed and
tested on actual hardware.  Without the solution, rmmod an edac driver
would result in below deadlock:

root@localhost:/root> rmmod mv64x60_edac
EDAC DEBUG: mv64x60_dma_err_remove()
EDAC DEBUG: edac_device_del_device()
EDAC DEBUG: find_edac_device_by_dev()

(hang for a moment)

INFO: task edac-poller:2030 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
edac-poller   D 00000000     0  2030      2
Call Trace:
[df159dc0] [c0071e3c] free_hot_cold_page+0x17c/0x304 (unreliable)
[df159e80] [c000a024] __switch_to+0x6c/0xa0
[df159ea0] [c03587d8] schedule+0x2f4/0x4d8
[df159f00] [c03598a8] __mutex_lock_slowpath+0xa0/0x174
[df159f40] [e1030434] edac_device_workq_function+0x28/0xd8 [edac_core]
[df159f60] [c003beb4] run_workqueue+0x114/0x218
[df159f90] [c003c674] worker_thread+0x5c/0xc8
[df159fd0] [c004106c] kthread+0x5c/0xa0
[df159ff0] [c0013538] original_kernel_thread+0x44/0x60
INFO: task rmmod:2062 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
rmmod         D 0ff2c9fc     0  2062   1839
Call Trace:
[df119c00] [c0437a74] 0xc0437a74 (unreliable)
[df119cc0] [c000a024] __switch_to+0x6c/0xa0
[df119ce0] [c03587d8] schedule+0x2f4/0x4d8
[df119d40] [c03591dc] schedule_timeout+0xb0/0xf4

Signed-off-by: Linus Torvalds

dev_name introduction fall out fix

2008-05-05T22:08:38+00:00

Commit 06916639e2fed9ee475efef2747a1b7429f8fe76 ("driver-core: add
dev_name() to help transition away from using bus_id") added a static
inline dev_name() and used it in dev_printk.

Unfortunately, drivers/edac/edac_core.h defines a macro called
dev_name().  Rename the latter.

Diagnosis by Tony Breeds and Michael Ellerman.

Signed-off-by: Stephen Rothwell 
Acked-by: Doug Thompson 
Signed-off-by: Linus Torvalds

edac: remove unneeded functions and add static accessor

2008-04-29T15:06:26+00:00

Collection of patches, merged into one, from Adrian that do the following:

1) This patch makes the following needlessly global functions static:
- edac_pci_get_log_pe()
- edac_pci_get_log_npe()
- edac_pci_get_panic_on_pe()
- edac_pci_unregister_sysfs_instance_kobj()
- edac_pci_main_kobj_setup()

2) Remove unneeded function edac_device_find()

3) Added #if 0 around function  edac_pci_find()

4) make the needlessly global edac_pci_generic_check() static

5) Removed function edac_check_mc_devices()

Doug Thompson modified Adrian's patches, to bettern represent
the direction of EDAC, and make them one patch.

Cc: Alan Cox 
Signed-off-by: Adrian Bunk 
Signed-off-by: Doug Thompson 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

edac: use the shorter LIST_HEAD for brevity

2008-04-29T15:06:26+00:00

Signed-off-by: Robert P. J. Day 
Acked-by: Doug Thompson 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers-edac: use round_jiffies_relative

2008-02-07T16:42:23+00:00

When rounding a relative timeout we need to use round_jiffies_relative().

Signed-off-by: Anton Blanchard 
Acked-by: Arjan van de Ven 
Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers-edac: turn on edac device error logging

2008-02-07T16:42:23+00:00

ENABLE the 'logging' of CE and UE events for the EDAC_DEVICE class of error
harvester in EDAC

Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/edac: fix edac_device sysfs corner case bug

2007-07-19T17:04:57+00:00

Some simple fixes to properly reference counter values from the block
attribute level of edac_device objects.  Properly sequencing the array pointer
was added, resulting in correct identification of block level attributes from
their base class functions.

Added more verbose debug statement for event tracking.

Also during some corner testing, found a bug in the store/show sequence
of operations for the block attribute/controls management.

An old intermediate structure for 'blocks' was still in the processing
pipeline.  This patch removes that old structure and correctly utilizes the
new struct edac_dev_sysfs_block_attribute for passing control from the sysfs
to the low level store/show function of the edac driver.

Now the proper kobj pointer to passed downward to the store/show
functions.

Signed-off-by: Doug Thompson 
Cc: Greg KH 
Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/edac: fix workq reset deadlock

2007-07-19T17:04:57+00:00

Fix mutex locking deadlock on the device controller linked list.  Was calling
a lock then a function that could call the same lock.  Moved the cancel workq
function to outside the lock

Added some short circuit logic in the workq code

Added comments of description

Code tidying

Signed-off-by: Doug Thompson 
Cc: Greg KH 
Cc: Alan Cox 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds