linux-toradex.git/drivers/firewire/fw-device.c, branch v2.6.27.20

firewire: clean up fw_card reference counting

2008-07-14T11:06:03+00:00

This is a functionally equivalent replacement of the current reference
counting of struct fw_card instances.  It only converts it to common
idioms as suggested by Kristian Høgsberg:
  - struct kref replaces atomic_t as the counter.
  - wait_for_completion is used to wait for all card users to complete.

BTW, it may make sense to count card->flush_timer and card->work as
card users too.

Signed-off-by: Stefan Richter

Convert asm/semaphore.h users to linux/semaphore.h

2008-04-19T02:22:54+00:00

Signed-off-by: Matthew Wilcox

firewire: replace more hex values with defined csr constants

2008-04-18T15:55:36+00:00

Trivial change to replace more meaningless (to the untrained eye) hex
values with defined CSR constants.

Signed-off-by: Jarod Wilson 
Signed-off-by: Stefan Richter

firewire: reread config ROM when device reset the bus

2008-04-18T15:55:36+00:00

When a device changes its configuration ROM, it announces this with a
bus reset.  firewire-core has to check which node initiated a bus reset
and whether any unit directories went away or were added on this node.

Tested with an IOI FWB-IDE01AB which has its link-on bit set if bus
power is available but does not respond to ROM read requests if self
power is off.  This implements
  - recognition of the units if self power is switched on after fw-core
    gave up the initial attempt to read the config ROM,
  - shutdown of the units when self power is switched off.

Also tested with a second PC running Linux/ieee1394.  When the eth1394
driver is inserted and removed on that node, fw-core now notices the
addition and removal of the IPv4 unit on the ieee1394 node.

Signed-off-by: Stefan Richter

firewire: replace static ROM cache by allocated cache

2008-04-18T15:55:35+00:00

read_bus_info_block() is repeatedly called by workqueue jobs.
These will step on each others toes eventually if there are multiple
workqueue threads, and we end up with corrupt config ROM images.

Signed-off-by: Stefan Richter

firewire: fix crash in automatic module unloading

2008-03-02T11:35:46+00:00

"modprobe firewire-ohci; sleep .1; modprobe -r firewire-ohci" used to
result in crashes like this:

    BUG: unable to handle kernel paging request at ffffffff8807b455
    IP: []
    PGD 203067 PUD 207063 PMD 7c170067 PTE 0
    Oops: 0010 [1] PREEMPT SMP
    CPU 0
    Modules linked in: i915 drm cpufreq_ondemand acpi_cpufreq freq_table applesmc input_polldev led_class coretemp hwmon eeprom snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss button thermal processor sg snd_hda_intel snd_pcm snd_timer snd snd_page_alloc sky2 i2c_i801 rtc [last unloaded: crc_itu_t]
    Pid: 9, comm: events/0 Not tainted 2.6.25-rc2 #3
    RIP: 0010:[]  []
    RSP: 0018:ffff81007dcdde88  EFLAGS: 00010246
    RAX: ffff81007dc95040 RBX: ffff81007dee5390 RCX: 0000000000005e13
    RDX: 0000000000008c8b RSI: 0000000000000001 RDI: ffff81007dee5388
    RBP: ffff81007dc5eb40 R08: 0000000000000002 R09: ffffffff8022d05c
    R10: ffffffff8023b34c R11: ffffffff8041a353 R12: ffff81007dee5388
    R13: ffffffff8807b455 R14: ffffffff80593bc0 R15: 0000000000000000
    FS:  0000000000000000(0000) GS:ffffffff8055a000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
    CR2: ffffffff8807b455 CR3: 0000000000201000 CR4: 00000000000006e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Process events/0 (pid: 9, threadinfo ffff81007dcdc000, task ffff81007dc95040)
    Stack:  ffffffff8023b396 ffffffff88082524 0000000000000000 ffffffff8807d9ae
    ffff81007dc5eb40 ffff81007dc9dce0 ffff81007dc5eb40 ffff81007dc5eb80
    ffff81007dc9dce0 ffffffffffffffff ffffffff8023be87 0000000000000000
    Call Trace:
    [] ? run_workqueue+0xdf/0x1df
    [] ? worker_thread+0xd8/0xe3
    [] ? autoremove_wake_function+0x0/0x2e
    [] ? worker_thread+0x0/0xe3
    [] ? kthread+0x47/0x74
    [] ? trace_hardirqs_on_thunk+0x35/0x3a
    [] ? child_rip+0xa/0x12
    [] ? restore_args+0x0/0x3d
    [] ? kthreadd+0x14c/0x171
    [] ? kthreadd+0x14c/0x171
    [] ? kthread+0x0/0x74
    [] ? child_rip+0x0/0x12

    Code:  Bad RIP value.
    RIP  []
    RSP 
    CR2: ffffffff8807b455
    ---[ end trace c7366c6657fe5bed ]---

Note that this crash happened _after_ firewire-core was unloaded.  The
shared workqueue tried to run firewire-core's device initialization jobs
or similar jobs.

The fix makes sure that firewire-ohci and hence firewire-core is not
unloaded before all device shutdown jobs have been completed.  This is
determined by the count of device initializations minus device releases.

Also skip useless retries in the node initialization job if the node is
to be shut down.

Signed-off-by: Stefan Richter 
Signed-off-by: Jarod Wilson

firewire: log GUID of new devices

2008-02-16T14:40:34+00:00

This should help to interpret user reports.  E.g. one can look up the
vendor OUI (first three bytes of the GUID) and thus tell what is what.

Also simplifies the math in the GUID sysfs attribute.

Signed-off-by: Stefan Richter 
Signed-off-by: Jarod Wilson

firewire: fix "kobject_add failed for fw* with -EEXIST"

2008-02-16T14:40:33+00:00

There is a race between shutdown and creation of devices:  fw-core may
attempt to add a device with the same name of an already existing
device.  http://bugzilla.kernel.org/show_bug.cgi?id=9828

Impact of the bug:  Happens rarely (when shutdown of a device coincides
with creation of another), forces the user to unplug and replug the new
device to get it working.

The fix is obvious:  Free the minor number *after* instead of *before*
device_unregister().  This requires to take an additional reference of
the fw_device as long as the IDR tree points to it.

And while we are at it, we fix an additional race condition:
fw_device_op_open() took its reference of the fw_device a little bit too
late, hence was in danger to access an already invalid fw_device.

Signed-off-by: Stefan Richter

firewire: fw-core: react on bus resets while the config ROM is being fetched

2008-01-30T21:22:28+00:00

read_rom() obtained a fresh new fw_device.generation for each read
transaction.  Hence it was able to continue reading in the middle of the
ROM even if a bus reset happened.  However the device may have modified
the ROM during the reset.  We would end up with a corrupt fetched ROM
image then.

Although all of this is quite unlikely, it is not impossible.
Therefore we now restart reading the ROM if the bus generation changed.

Note, the memory barrier in read_rom() is still necessary according to
tests by Jarod Wilson, despite of the ->generation access being moved up
in the call chain.

Signed-off-by: Stefan Richter 

This is essentially what I've been beating on locally, and I've yet to hit
another config rom read failure with it.

Signed-off-by: Jarod Wilson

firewire: enforce access order between generation and node ID, fix "giving up on config rom"

2008-01-30T21:22:27+00:00

fw_device.node_id and fw_device.generation are accessed without mutexes.
We have to ensure that all readers will get to see node_id updates
before generation updates.

Fixes an inability to recognize devices after "giving up on config rom",
https://bugzilla.redhat.com/show_bug.cgi?id=429950

Signed-off-by: Stefan Richter 

Reviewed by Nick Piggin .

Verified to fix 'giving up on config rom' issues on multiple system and
drive combinations that were previously affected.

Signed-off-by: Jarod Wilson 
Signed-off-by: Kristian Høgsberg