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path: root/drivers/firewire/fw-topology.c
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2008-07-14firewire: fix race of bus reset with request transmissionStefan Richter
Reported by Jay Fenlason: A bus reset tasklet may call fw_flush_transactions and touch transactions (call their callback which will free them) while the context which submitted the transaction is still inserting it into the transmission queue. A simple solution to this problem is to _not_ "flush" the transactions because of a bus reset (complete the transcations as 'cancelled'). They will now simply time out (completed as 'cancelled' by the split-timeout timer). Jay Fenlason thought of this fix too but I was quicker to type it out. :-) Background: Contexts which access an instance of struct fw_transaction are: 1. the submitter, until it inserted the packet which is embedded in the transaction into the AT req DMA, 2. the AsReqTrContext tasklet when the request packet was acked by the responder node or transmission to the responder failed, 3. the AsRspRcvContext tasklet when it found a request which matched an incoming response, 4. the card->flush_timer when it picks up timed-out transactions to cancel them, 5. the bus reset tasklet when it cancels transactions (this access is eliminated by this patch), 6. a process which shuts down an fw_card (unregisters it from fw-core when the controller is unbound from fw-ohci) --- although in this case there shouldn't really be any transactions anymore because we wait until all card users finished their business with the card. All of these contexts run concurrently (except for the 6th, presumably). The 1st is safe against the 2nd and 3rd because of the way how a request packet is carefully submitted to the hardware. A race between 2nd and 3rd has been fixed a while ago (bug 9617). The 4th is almost safe against 1st, 2nd, 3rd; there are issues with it if huge scheduling latencies occur, to be fixed separately. The 5th looks safe against 2nd, 3rd, and 4th but is unsafe against 1st. Maybe this could be fixed with an explicit state variable in struct fw_transaction. But this would require fw_transaction to be rewritten as only dynamically allocatable object with reference counting --- not a good solution if we also can simply kill this 5th accessing context (replace it by the 4th). Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-04-18firewire: fix synchronization of gap countsStefan Richter
Fix: The fact that nodes had different gap counts would be overlooked if the bus manager code would pick gap count 63 because of beta repeaters or because of very large hop counts. In this case, the bus manager code would miss that it actually has to send the PHY config packet with gap count 63. Related trivial changes: Use bool for an int used as bool, touch up some comments. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-04-18firewire: reread config ROM when device reset the busStefan Richter
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 <stefanr@s5r6.in-berlin.de>
2008-03-14firewire: warn on fatal condition in topology codeStefan Richter
If this ever happens to anybody, we want to have it in his log. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-03-02firewire: potentially invalid pointers used in fw_card_bm_workStefan Richter
The bus management workqueue job was in danger to dereference NULL pointers. Also, after having temporarily lifted card->lock, a few node pointers and a device pointer may have become invalid. Add NULL pointer checks and get the necessary references. Also, move card->local_node out of fw_card_bm_work's sight during shutdown of the card. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Jarod Wilson <jwilson@redhat.com>
2008-01-30firewire: enforce access order between generation and node ID, fix "giving ↵Stefan Richter
up on config rom" 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 <stefanr@s5r6.in-berlin.de> Reviewed by Nick Piggin <nickpiggin@yahoo.com.au>. Verified to fix 'giving up on config rom' issues on multiple system and drive combinations that were previously affected. Signed-off-by: Jarod Wilson <jwilson@redhat.com> Signed-off-by: Kristian Høgsberg <krh@redhat.com>
2007-10-17firewire: in-code doc updates.Yann Dirson
Signed-off-by: Yann Dirson <ydirson@altern.org> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (update)
2007-10-17firewire: a header cleanupStefan Richter
fw_node() is not used (and not useful) outside fw-topology.c. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-07-10firewire: simplify a struct typeStefan Richter
cleanup after "firewire: support S100B...S400B and link slower than PHY" Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Kristian Høgsberg <krh@redhat.com>
2007-07-10firewire: optimize gap count with 1394b leaf nodesStefan Richter
Table-based gap count optimization cannot be used if 1394b repeater PHYs are present. But it does work with 1394b leaf nodes. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Kristian Høgsberg <krh@redhat.com>
2007-07-10firewire: missing newline in printkStefan Richter
Also remove some errno printouts which will be shown by infrastructure code anyway. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-05-10firewire: Always use parens with sizeof.Kristian Høgsberg
Signed-off-by: Kristian Hoegsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-05-10firewire: Uppercase most macro names.Kristian Høgsberg
Signed-off-by: Kristian Hoegsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-05-10firewire: Coding style cleanup: no spaces after function names.Kristian Høgsberg
Signed-off-by: Kristian Hoegsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-05-10firewire: Clean up comment style.Kristian Høgsberg
Drop filenames from file preamble, drop editor annotations and use standard indent style for block comments. Signed-off-by: Kristian Hoegsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (fixed typo)
2007-05-10firewire: Use lib/ implementation of CRC ITU-T.Kristian Høgsberg
With the CRC ITU-T implementation available in lib/ we can use that instead. This also fixes a bug in the topology map crc computation. Signed-off-by: Kristian Hoegsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (fixed Kconfig)
2007-03-28firewire: Don't set card->irm_node before we have a new valid topology.Kristian Høgsberg
In case the topology build fails, we want to retain the old topology info until another reset finishes and results in a valid new tree. If we clear card->irm_node to NULL and the topology build fails, we end up dereferencing a NULL pointer in a few places. Signed-off-by: Kristian Høgsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: Implement topology map and fix a couple of loopback bugs.Kristian Høgsberg
Signed-off-by: Kristian Høgsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: Schedule topology work before calling driver update functions.Kristian Høgsberg
This prevents superfluous bus traffic as fw-sbp2 logs in only to get kicked off the device by another bus reset as the driver core does bus management. Scheduling it this way lets the driver core finish bus management before higher level drivers get the update callback. Signed-off-by: Kristian Høgsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: Implement compliant bus management.Kristian Høgsberg
Signed-off-by: Kristian Høgsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: fix compilation with gcc 3.4Stefan Richter
drivers/firewire/fw-topology.c: In function `report_found_node': drivers/firewire/fw-topology.c:345: error: `typeof' applied to a bit-field drivers/firewire/fw-topology.c:345: error: `typeof' applied to a bit-field Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: Implement gap count optimization.Kristian Høgsberg
Signed-off-by: Kristian Høgsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: consistent usage of node_idStefan Richter
Definitions as per IEEE 1212 and IEEE 1394: Node ID: Concatenation of bus ID and local ID. 16 bits long. Bus ID: Identifies a particular bus within a group of buses interconnected by bus bridges. Local ID: Identifies a particular node on a bus. PHY ID: Local ID of IEEE 1394 nodes. 6 bits long. Never ever use a variable called node_id for anything else than a node ID. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: whitespace adjustmentsStefan Richter
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Kristian Høgsberg <krh@redhat.com>
2007-03-09firewire: cleanupsAdrian Bunk
This patch contains the following cleanups: - "extern inline" -> "static inline" - fw-topology.c: make struct fw_node_create static Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: Add device probing and sysfs integration.Kristian Høgsberg
Signed-off-by: Kristian Høgsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2007-03-09firewire: Add core firewire stack.Kristian Høgsberg
Signed-off-by: Kristian Høgsberg <krh@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>