There are situations when nodes vanish from the bus and come back in
quickly thereafter:
- When certain bus-powered hubs are plugged in,
- when certain disk enclosures are switched from self-power to bus
power or vice versa and break the daisy chain during the transition,
- when the user plugs a cable out and quickly plugs it back in, e.g.
to reorder a daisy chain (works on Mac OS X if done quickly enough),
- when certain hubs temporarily malfunction during high bus traffic.
The ieee1394 driver's nodemgr already contained a function to set
vanished nodes aside into "limbo"; i.e. they wouldn't actually be
deleted right away. (In fact, only unloading the driver or writing into
an obscure sysfs attribute would delete them eventually.) If nodes
reappeared later, they would be resurrected out of limbo.
Moving nodes into and out of limbo was accompanied with calling the
.suspend() and .resume() driver methods of the drivers which were bound
to a respective node's unit directories. Not only is this somewhat
strange due to the intended use of these driver methods for power
management, also the sbp2 driver in particular does not implement
.suspend() and .resume(). Hence sbp2 would be disconnected from devices
in situations as listed above.
We now:
- leave drivers bound when nodes go into limbo,
- call the drivers' .update() when nodes come out of limbo,
- automatically delete in-limbo nodes 3 seconds after the last
bus reset and bus rescan.
- Because of the automatic removal, the now obsolete bus attribute
/sys/bus/ieee1394/destroy_node is removed.
This especially lets sbp2 survive brief disconnections. You can for
example yank a disk's cable and plug it back in while reading the
respective disk with dd, but dd will happily continue as if nothing
happened.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Regression since commit 73cf60232e,
"ieee1394: use class iteration api": The two loops for (1.) driver
updates and (2.) driver probes were replaced by a single loop with
bogus needs_probe checks. Hence updates and probes were now intermixed,
and especially sbp2 updates (reconnects) held up longer than necessary.
While we fix it, change the needs_probe flag to bool type for clarity.
Tested by Damien Benoist.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Here is a straightforward conversion to "struct device". The "struct
class_device" will be removed from the kernel.
It seems to work fine for me with and without CONFIG_SYSFS_DEPRECATED
set.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
With "modprobe sbp2 long_ieee1394_id=y", the format of
/sys/bus/scsi/devices/*:*:*:*/ieee1394_id is changed from e.g.
0001041010004beb:0:0 to 0001041010004beb:00042c:0000.
The longer format fully conforms to object identifier sizes as per
SAM(-2...4) and reflects what the SAM target port identifier is meant to
contain: A Discovery ID allegedly specified by ISO/IEC 13213:1994 ---
however there is no such thing; the authors of SAM probably meant
Directory ID). Especially target nodes with multiple dynamically added
targets may use Directory IDs to persistently identify target ports.
The new format is independent of implementation details of nodemgr.
Thus the same ieee1394_id attribute format can be implemented in the new
firewire stack.
The ieee1394_id is typically used to create persistently named links in
/dev/disk/by-id.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This patch contains the scheduled IEEE1394_OUI_DB removal.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Update: Also remove drivers/ieee1394/.gitignore.
Remove now unused struct members in drivers/ieee1394/nodemgr.h.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This patch consolidates some bookkeeping for driver registering. It
closely models what pci_register_driver() does. The main addition is
that the owner of the driver is set, so we get a proper symlink
for /sys/bus/ieee1394/driver/*/module.
Also moves setting of name and bus type into nodemgr. Because of this,
we can remove the EXPORT_SYMBOL for ieee1394_bus_type, since it's now
only used in ieee1394.ko.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This patch reduces the size of struct hpsb_host and also removes
semaphores from ieee1394_transactions.c. On i386, struct hpsb_host
shrinks from 10656 bytes to 6688 bytes. This is accomplished by
- using a single wait_queue for hpsb_get_tlabel instead of many
instances of semaphores,
- using a single lock to serialize access to all tlabel pools (the
protected code regions are small, i.e. lock contention very low),
- omitting the sysfs attribute tlabels_allocations.
Drawback: In the rare case that a process needs to sleep because all
transaction labels for the node are temporarily exhausted, it is also
woken up if a tlabel for a different node became free, checks for an
available tlabel, and is put to sleep again. The check is not costly
and the situation occurs extremely rarely. (Tlabels are typically
only exhausted if there was no context switch to the khpsbpkt thread
which recycles tlables.) Therefore the benefit of reduced tpool size
outweighs this drawback.
The sysfs attributes tlabels_free and tlabels_mask are not compiled
anymore unless CONFIG_IEEE1394_VERBOSEDEBUG is set.
The by far biggest member of struct hpsb_host, the struct csr_control
csr (5272 bytes on i386), is now placed at the end of struct hpsb_host.
Note, hpsb_get_tlabel calls the macro wait_event_interruptible with a
condition argument which has a side effect (allocation of a tlabel and
manipulation of the packet). This side effect happens only if the
condition is true. The patch relies on wait_event_interruptible not
evaluating the condition again after it became true.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Remove unnecessary includes, add missing includes.
Use forward type declarations for some structs.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Adjust tabulators, line wraps, empty lines, and comment style.
Update comments in ieee1394_transactions.h and highlevel.h.
Fix typo in comment in csr.h.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
