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2025-12-04Merge tag 'firewire-updates-6.19' of ↵Linus Torvalds1-14/+11
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394 Pull firewire updates from Takashi Sakamoto: "This includes two changes for core functions, which affects all use cases of this subsystem: - Handle per-device interoperability quirks Some devices have quirks affecting interoperability. To identify such quirks at an early stages of device detection, the step for reading the configuration ROM contents has been changed. As a side effect, the entire detection process is now performed at the basic transaction speed (S100), without a trial to probe higher supported speeds. With this change, the following devices should now work with fewer issues: - TASCAM FW-1884, FW-1804, and FW-1082 - MOTU Audio Express - Safer removals of host card There was a race condition between host card removal and handling of bus reset events in the workqueue. This appears to be a long standing issue, and recent changes to use more workqueues escalate it. To solve it, a new callback has been added to the 1394 OHCI PCI driver to unregister the interrupt sources and wait for workqueue completions when removing a card instance" * tag 'firewire-updates-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394: firewire: core: abort pending transactions at card removal firewire: core: add WQ_UNBOUND to alloc_workqueue users firewire: core: clear sources of hardware interrupt at card removal firewire: core: code refactoring to find and pop transaction entry firewire: core: code refactoring to remove transaction entry firewire: core: use cleanup function to release cached configuration ROM ALSA: firewire-tascam: reserve resources for transferred isochronous packets at S400 firewire: core: handle device quirk of TASCAM FW-1884/FW-1804/FW-1082 firewire: core: determine transaction speed after detecting quirks firewire: core: code refactoring to compute transaction speed firewire: core: handle device quirk of MOTU Audio Express firewire: core: detect device quirk when reading configuration ROM
2025-11-14firewire: core: Initialize topology_map.lockVille Syrjälä1-0/+2
Lockdep barfs on the new uninitialized spinlock. Initialize it. protip: enable lockdep (CONFIG_PROVE_LOCKING=y) when doing locking changes firewire_ohci 0000:02:01.1: added OHCI v1.10 device as card 0, 4 IR + 4 IT contexts, quirks 0x11 INFO: trying to register non-static key. The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator. CPU: 0 UID: 0 PID: 1042 Comm: irq/17-firewire Not tainted 6.17.0-rc2-cl-bisect2-00026-g7d138cb269db #136 PREEMPT Hardware name: Dell Inc. Latitude E5400 /0D695C, BIOS A19 06/13/2013 Call Trace: <TASK> dump_stack_lvl+0x6d/0xa0 register_lock_class+0x783/0x790 ? find_held_lock+0x2b/0x80 ? __mod_timer+0x110/0x320 ? __mod_timer+0x110/0x320 __lock_acquire+0x405/0x2600 lock_acquire+0xca/0x2e0 ? fw_core_handle_bus_reset+0x888/0xca0 [firewire_core] ? fw_core_handle_bus_reset+0x878/0xca0 [firewire_core] ? fw_core_handle_bus_reset+0x878/0xca0 [firewire_core] _raw_spin_lock+0x2e/0x40 ? fw_core_handle_bus_reset+0x888/0xca0 [firewire_core] fw_core_handle_bus_reset+0x888/0xca0 [firewire_core] handle_selfid_complete_event+0x35c/0x7a0 [firewire_ohci] ? irq_thread+0x8d/0x280 irq_thread_fn+0x18/0x50 irq_thread+0x15a/0x280 ? irq_check_status_bit+0x100/0x100 ? lockdep_hardirqs_on+0x78/0x100 ? irq_finalize_oneshot.part.0+0xc0/0xc0 ? irq_forced_thread_fn+0x60/0x60 kthread+0x114/0x200 ? kthreads_online_cpu+0x110/0x110 ret_from_fork+0x158/0x1e0 ? kthreads_online_cpu+0x110/0x110 ret_from_fork_asm+0x11/0x20 </TASK> Reported-by: Erhard Furtner <erhard_f@mailbox.org> Fixes: 7d138cb269db ("firewire: core: use spin lock specific to topology map") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-11-14firewire: core: abort pending transactions at card removalTakashi Sakamoto1-0/+1
IEEE 1394 defines the split, concatenated, and unified transaction. To support the split transaction, core function uses linked list to maintain the transactions waiting for acknowledge packet. After clearing sources of hardware interrupts, the acknowledge packet is no longer handled, therefore it is required to abort the pending transactions. This commit executes callback with RCODE_CANCELLED for the pending transactions at card removal. Link: https://lore.kernel.org/r/20251111223834.311287-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-11-09firewire: core: clear sources of hardware interrupt at card removalTakashi Sakamoto1-0/+3
Due to the factors external to the system, hardware events may still be handled while a card instance is being removed. The sources of hardware IRQs should be cleared during card removal so that workqueues can be safely destroyed. This commit adds a disable callback to the underlying driver operations. After this callback returns, the underlying driver guarantees that it will no longer handle hardware events. Link: https://lore.kernel.org/r/20251109065525.163464-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-10-13firewire: core: detect device quirk when reading configuration ROMTakashi Sakamoto1-14/+7
Every time the bus manager runs, the cached configuration ROM content of the IRM device is investigated to detect device-specific quirks. This detection can be performed in advance when reading the configuration ROM. This commit adds device quirk flags to the fw_device structure, and initializes them after reading the bus information block of the configuration ROM. The quirk flags are immutable once the configuration ROM has been read. Although they are likely accessed concurrently only by the bus manager, this commit ensures safe access by preventing torn writes and reads using the WRITE_ONCE()/READ_ONCE() macros. Link: https://lore.kernel.org/r/20251013140311.97159-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-24Revert "firewire: core: shrink critical section of fw_card spinlock in bm_work"Takashi Sakamoto1-8/+30
This reverts commit 582310376d6e9a8d261b682178713cdc4b251af6. The bus manager work has the race condition against fw_destroy_nodes() called by fw_core_remove_card(). The acquition of spin lock of fw_card is left as is again. Link: https://lore.kernel.org/r/20250924131823.262136-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-19firewire: core: minor code refactoring to delete useless local variableTakashi Sakamoto1-11/+4
The do_reset local variable has less merit. Let's remove it. Link: https://lore.kernel.org/r/20250918235448.129705-7-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-19firewire: core; eliminate pick_me goto labelTakashi Sakamoto1-50/+51
This commit uses condition statements instead of pick_me goto label. Link: https://lore.kernel.org/r/20250918235448.129705-6-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-19firewire: core: code refactoring to split contention procedure for bus managerTakashi Sakamoto1-96/+127
The precedure to contend for bus manager has much code. It is better to split it into a helper function. This commit refactors in the point. Link: https://lore.kernel.org/r/20250918235448.129705-5-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-19firewire: core: code refactoring for the case of generation mismatchTakashi Sakamoto1-95/+93
Current implementation stores the bus generation at which the bus manager contending procedure finishes. The condition for the procedure is the mismatch of the stored generation against current bus generation. This commit refactors the code for the contending procedure. Two existing branches are put into a new branch to detect the generation mismatch, thus the most of change is indentation. Link: https://lore.kernel.org/r/20250918235448.129705-4-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-19firewire: core: use switch statement to evaluate transaction result to ↵Takashi Sakamoto1-26/+24
CSR_BUS_MANAGER_ID The result of the lock transaction to swap bus manager on isochronous resource manager looks like an ad-hoc style. It is hard to read. This commit uses switch statement to evaluate the result. Link: https://lore.kernel.org/r/20250918235448.129705-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-19firewire: core: remove useless generation checkTakashi Sakamoto1-8/+6
Two functions, fw_core_handle_bus_reset() and bm_work(), are serialized by a commit 3d91fd440cc7 ("firewire: core: disable bus management work temporarily during updating topology"). Therefore the generation member of fw_card is immutable in bm_work(). This commit removes useless generation check in bm_work(). Link: https://lore.kernel.org/r/20250918235448.129705-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-17firewire: core: shrink critical section of fw_card spinlock in bm_workTakashi Sakamoto1-22/+8
Now fw_core_handle_bus_reset() and bm_work() are serialized. Some members of fw_card are free to access in bm_work() This commit shrinks critical section of fw_card spinlock in bm_work() Link: https://lore.kernel.org/r/20250917000347.52369-4-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-16firewire: core: use spin lock specific to timer for split transactionTakashi Sakamoto1-4/+6
At present the parameters to compute timeout time for split transaction is protected by card-wide spin lock, while it is not necessarily convenient in a point to narrower critical section. This commit adds and uses another spin lock specific for the purpose. Link: https://lore.kernel.org/r/20250915234747.915922-6-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-16firewire: core: use spin lock specific to transactionTakashi Sakamoto1-4/+8
The list of instance for asynchronous transaction to wait for response subaction is maintained as a member of fw_card structure. The card-wide spinlock is used at present for any operation over the list, however it is not necessarily suited for the purpose. This commit adds and uses the spin lock specific to maintain the list. Link: https://lore.kernel.org/r/20250915234747.915922-5-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-16firewire: core: maintain phy packet receivers locally in cdev layerTakashi Sakamoto1-1/+0
The list of receivers for phy packet is used only by cdev layer, while it is maintained as a member of fw_card structure. This commit maintains the list locally in cdev layer. Link: https://lore.kernel.org/r/20250915234747.915922-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-15firewire: core: use helper macro to compare against current jiffiesTakashi Sakamoto1-2/+2
The pattern of calling either time_before64() or time_after64() with get_jiffies_64() can be replaced with the corresponding helper macros. Link: https://lore.kernel.org/r/20250915024232.851955-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-15firewire: core: use helper macros instead of direct access to HZTakashi Sakamoto1-10/+7
There are some macros available to convert usecs, msecs, and secs into jiffies count. Link: https://lore.kernel.org/r/20250915024232.851955-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-13firewire: core: use macro expression for not-registered state of BUS_MANAGER_IDTakashi Sakamoto1-4/+8
The value of BUS_MANAGER_ID register has 0x3f when no node_id is registered. Current implementation uses hard-coded numeric literal but in the case the macro expression is preferable since it is easy to distinguish the state from node ID mask. This commit applies the idea. Link: https://lore.kernel.org/r/20250913105737.778038-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-13firewire: core: use macro expression for gap count mismatchTakashi Sakamoto1-1/+1
The gap_count field is assigned to zero when mismatch is detected. In such case, the macro expression is preferable since it is easy to understand the situation. This commit applies the idea. Link: https://lore.kernel.org/r/20250913105737.778038-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-12firewire: core: remove useless lockdep_assert_held()Takashi Sakamoto1-2/+0
The bm_work work item should be scheduled after holding fw_card reference counting. At a commit 25feb1a96e21 ("firewire: core: use cleanup function in bm_work"), I misinterpreted it as fw_card spinlock and inserted lockdep_assert_hold() wrongly. This commit removes the useless line. Fixes: 25feb1a96e21 ("firewire: core: use cleanup function in bm_work") Link: https://lore.kernel.org/r/20250911221312.678076-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: core: code refactoring whether root node is cycle master capableTakashi Sakamoto1-5/+3
The check of cycle master capability in root node is currently just in a condition branch. In this case, the required variable should be within the branch. This commit is just for the purpose. Link: https://lore.kernel.org/r/20250908012108.514698-12-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: core: code refactoring to investigate root node for bus managerTakashi Sakamoto1-29/+27
In the middle of bm_work function, both the value of gap_count and the state of root node are investigated. Current implementation is not a good shape since the investigation is aligned to be flat. This commit refactors the investigation with two large branches. Link: https://lore.kernel.org/r/20250908012108.514698-11-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: core: code refactoring to detect both IEEE 1394:1995 IRM and Canon ↵Takashi Sakamoto1-11/+11
MV5i The detection of IEEE 1394:1995 and Canon MV5i is just required within some of the condition branches. In this case, these check can be capsulated within these branches. This commit refactors the checks. Link: https://lore.kernel.org/r/20250908012108.514698-10-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: core: refer fw_card member to initiate bus reset under acquiring lockTakashi Sakamoto1-26/+26
The gap_count member of fw_card structure is referred when initiate bus reset. This reference is done out of acquiring lock. This is not good. This commit takes the reference within the acquiring lock, with additional code refactoring. Link: https://lore.kernel.org/r/20250908012108.514698-9-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: core: code refactoring to evaluate transaction result to ↵Takashi Sakamoto1-14/+16
CSR_BUS_MANAGER_ID The call of bm_work should be done after acquiring spin lock of fw_card. For asynchronous transaction, the lock should be released temporarily due to event waiting. A commit 27310d561622 ("firewire: core: use guard macro to maintain properties of fw_card") applied scoped_guard() to the bm_work function, however it looks hard to follow to the control flow. This commit refactors the spin lock acquisition after the transaction. Link: https://lore.kernel.org/r/20250908012108.514698-8-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: ohci: localize transaction data and rcode per condition branchTakashi Sakamoto1-10/+11
The function local variable, transaction_data, in bm_work function is conditionally used. In the case, the branch-level variable is sometimes useful. This commit uses this idea. Link: https://lore.kernel.org/r/20250908012108.514698-7-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: core: use cleanup function in bm_workTakashi Sakamoto1-17/+16
In "bm_work" function, the references to fw_card and fw_node are released at last. This is achieved by using goto statements. For this case, the kernel cleanup framework is available. This commit uses the framework to remove these statements. Link: https://lore.kernel.org/r/20250908012108.514698-6-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: core: add helper functions to access to fw_device data in fw_node ↵Takashi Sakamoto1-2/+2
structure The data mbmer in fw_node structure is an opaque pointer, while nowadays it is just used to refer to fw_device associated with the fw_node. This commit redefines the opaque pointer to a pointer to fw_device structure, and adds some helper functions to set/get it. Link: https://lore.kernel.org/r/20250908012108.514698-5-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: ohci: use return value from fw_node_get()Takashi Sakamoto1-2/+1
The programming pattern, referring after increasing reference count, is supported by fw_node_get(). This commit simplify the programming pattern. Link: https://lore.kernel.org/r/20250908012108.514698-4-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-09-08firewire: core: utilize cleanup function to release workqueue in error pathTakashi Sakamoto1-18/+22
The helper macro, retain_and_null_ptr(), introduced by a commit 092d00ead733 ("cleanup: Provide retain_and_null_ptr()") in v6.16 kernel, is useful in the error path to release the part of structure member. This commit uses the relatively new function. Link: https://lore.kernel.org/r/20250908012108.514698-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-06-17firewire: core: minor code refactoring to localize table of gap countTakashi Sakamoto1-4/+3
The table for gap count is accessed by a single function. In this case, it can be localized to the function. Link: https://lore.kernel.org/r/20250617004320.477421-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-06-15firewire: core: allocate workqueue for AR/AT request/response contextsTakashi Sakamoto1-14/+34
Some tasklets (softIRQs) are still used as bottom-halves to handle events for 1394 OHCI AR/AT contexts. However, using softIRQs for IRQ bottom halves is generally discouraged today. This commit adds a per-fw_card workqueue to accommodate the behaviour specified by the 1394 OHCI specification. According to the 1394 OHCI specification, system memory pages are reserved for each asynchronous DMA context. This allows concurrent operation across contexts. In the 1394 OHCI PCI driver implementation, the hardware generates IRQs either upon receiving asynchronous packets from other nodes (incoming) or after completing transmission to them (outgoing). These independent events can occur in the same transmission cycle, therefore the max_active parameter for the workqueue is set to the total number of AR/AT contexts (=4). The WQ_UNBOUND flag is used to allow the work to be scheduled on any available core, since there is little CPU cache affinity benefit for the data. Each DMA context uses a circular descriptor list in system memory, allowing deferred data processing in software as long as buffer overrun are avoided. Since the overall operation is sleepable except for small atomic regions, WQ_BH is not used. As the descriptors contain timestamps, WQ_HIGHPRI is specified to support semi-real-time processing. The asynchronous context is also used by the SCSI over IEEE 1394 protocol implementation (sbp2), which can be part of memory reclaim paths. Therefore, WQ_MEM_RECLAIM is required. To allow uses to adjust CPU affinity according to workload, WQ_SYSFS is specified so that workqueue attributes are exposed to user space. Link: https://lore.kernel.org/r/20250615133253.433057-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2025-06-09firewire: core: use from_work() macro to expand parent structure of work_structTakashi Sakamoto1-2/+2
A commit 60b2ebf48526 ("workqueue: Introduce from_work() helper for cleaner callback declarations") introduces a new macro to retrieve a poiner for the parent structure of the work item. It is convenient to reduce input text. This commit uses the macro in core functionalities. Link: https://lore.kernel.org/r/20250608233808.202355-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-09-04firewire: core: allocate workqueue to handle isochronous contexts in cardTakashi Sakamoto1-3/+30
This commit adds a workqueue dedicated for isochronous context processing. The workqueue is allocated per instance of fw_card structure to satisfy the following characteristics descending from 1394 OHCI specification: In 1394 OHCI specification, memory pages are reserved to each isochronous context dedicated to DMA transmission. It allows to operate these per-context pages concurrently. Software can schedule hardware interrupt for several isochronous context to the same cycle, thus WQ_UNBOUND is specified. Additionally, it is sleepable to operate the content of pages, thus WQ_BH is not used. The isochronous context delivers the packets with time stamp, thus WQ_HIGHPRI is specified for semi real-time data such as IEC 61883-1/6 protocol implemented by ALSA firewire stack. The isochronous context is not used by the implementation of SCSI over IEEE1394 protocol (sbp2), thus WQ_MEM_RECLAIM is not specified. It is useful for users to adjust cpu affinity of the workqueue depending on their work loads, thus WQ_SYS is specified to expose the attributes to user space. Tested-by: Edmund Raile <edmund.raile@protonmail.com> Link: https://lore.kernel.org/r/20240904125155.461886-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-08-05firewire: core: use guard macro to maintain properties of fw_cardTakashi Sakamoto1-9/+7
The core functions uses spinlock in instance of fw_card structure to protect concurrent access to properties in the instance. This commit uses guard macro to maintain the spinlock. Link: https://lore.kernel.org/r/20240805085408.251763-15-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-08-05firewire: core: use guard macro to maintain the list of cardTakashi Sakamoto1-26/+18
The core function maintains registered cards by list. The concurrent access to the list is protected by static mutex. This commit uses guard macro to maintain the mutex. Link: https://lore.kernel.org/r/20240805085408.251763-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-06-15firewire: core: record card index in tracepoinrts events derived from ↵Takashi Sakamoto1-3/+3
bus_reset_arrange_template The asynchronous transmission of phy packet is initiated on one of 1394 OHCI controller, however the existing tracepoints events has the lack of data about it. This commit adds card_index member into event structure to store the index of host controller in use, and prints it. Link: https://lore.kernel.org/r/20240613131440.431766-8-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-05-06Revert "firewire: core: option to log bus reset initiation"Takashi Sakamoto1-10/+0
This reverts commit 6732491243045f5a7e1995b4be5f3c964b579ebd. The former commit adds some alternative tracepoints events to replace the reverted kernel log messages. Link: https://lore.kernel.org/r/20240501073238.72769-5-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-05-06firewire: core: add tracepoints events for initiating bus resetTakashi Sakamoto1-0/+7
At a commit 673249124304 ("firewire: core: option to log bus reset initiation"), some kernel log messages were added to trace initiation of bus reset. The kernel log messages are really helpful, while nowadays it is not preferable just for debugging purpose. For the purpose, Linux kernel tracepoints is more preferable. This commit adds some alternative tracepoints events. Link: https://lore.kernel.org/r/20240501073238.72769-4-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-05-06firewire: core: option to log bus reset initiationAdam Goldman1-0/+10
Add a debug parameter to firewire-core, analogous to the one in firewire-ohci. When this is set to 1, log when we schedule, delay, or initiate a bus reset. Since FireWire bus resets can originate from any node on the bus, specific logging of the resets we initiate provides additional insight. Signed-off-by: Adam Goldman <adamg@pobox.com> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-02-29firewire: core: use long bus reset on gap count errorTakashi Sakamoto1-1/+13
When resetting the bus after a gap count error, use a long rather than short bus reset. IEEE 1394-1995 uses only long bus resets. IEEE 1394a adds the option of short bus resets. When video or audio transmission is in progress and a device is hot-plugged elsewhere on the bus, the resulting bus reset can cause video frame drops or audio dropouts. Short bus resets reduce or eliminate this problem. Accordingly, short bus resets are almost always preferred. However, on a mixed 1394/1394a bus, a short bus reset can trigger an immediate additional bus reset. This double bus reset can be interpreted differently by different nodes on the bus, resulting in an inconsistent gap count after the bus reset. An inconsistent gap count will cause another bus reset, leading to a neverending bus reset loop. This only happens for some bus topologies, not for all mixed 1394/1394a buses. By instead sending a long bus reset after a gap count inconsistency, we avoid the doubled bus reset, restoring the bus to normal operation. Signed-off-by: Adam Goldman <adamg@pobox.com> Link: https://sourceforge.net/p/linux1394/mailman/message/58741624/ Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-02-07firewire: core: send bus reset promptly on gap count errorTakashi Sakamoto1-1/+17
If we are bus manager and the bus has inconsistent gap counts, send a bus reset immediately instead of trying to read the root node's config ROM first. Otherwise, we could spend a lot of time trying to read the config ROM but never succeeding. This eliminates a 50+ second delay before the FireWire bus is usable after a newly connected device is powered on in certain circumstances. The delay occurs if a gap count inconsistency occurs, we are not the root node, and we become bus manager. One scenario that causes this is with a TI XIO2213B OHCI, the first time a Sony DSR-25 is powered on after being connected to the FireWire cable. In this configuration, the Linux box will not receive the initial PHY configuration packet sent by the DSR-25 as IRM, resulting in the DSR-25 having a gap count of 44 while the Linux box has a gap count of 63. FireWire devices have a gap count parameter, which is set to 63 on power-up and can be changed with a PHY configuration packet. This determines the duration of the subaction and arbitration gaps. For reliable communication, all nodes on a FireWire bus must have the same gap count. A node may have zero or more of the following roles: root node, bus manager (BM), isochronous resource manager (IRM), and cycle master. Unless a root node was forced with a PHY configuration packet, any node might become root node after a bus reset. Only the root node can become cycle master. If the root node is not cycle master capable, the BM or IRM should force a change of root node. After a bus reset, each node sends a self-ID packet, which contains its current gap count. A single bus reset does not change the gap count, but two bus resets in a row will set the gap count to 63. Because a consistent gap count is required for reliable communication, IEEE 1394a-2000 requires that the bus manager generate a bus reset if it detects that the gap count is inconsistent. When the gap count is inconsistent, build_tree() will notice this after the self identification process. It will set card->gap_count to the invalid value 0. If we become bus master, this will force bm_work() to send a bus reset when it performs gap count optimization. After a bus reset, there is no bus manager. We will almost always try to become bus manager. Once we become bus manager, we will first determine whether the root node is cycle master capable. Then, we will determine if the gap count should be changed. If either the root node or the gap count should be changed, we will generate a bus reset. To determine if the root node is cycle master capable, we read its configuration ROM. bm_work() will wait until we have finished trying to read the configuration ROM. However, an inconsistent gap count can make this take a long time. read_config_rom() will read the first few quadlets from the config ROM. Due to the gap count inconsistency, eventually one of the reads will time out. When read_config_rom() fails, fw_device_init() calls it again until MAX_RETRIES is reached. This takes 50+ seconds. Once we give up trying to read the configuration ROM, bm_work() will wake up, assume that the root node is not cycle master capable, and do a bus reset. Hopefully, this will resolve the gap count inconsistency. This change makes bm_work() check for an inconsistent gap count before waiting for the root node's configuration ROM. If the gap count is inconsistent, bm_work() will immediately do a bus reset. This eliminates the 50+ second delay and rapidly brings the bus to a working state. I considered that if the gap count is inconsistent, a PHY configuration packet might not be successful, so it could be desirable to skip the PHY configuration packet before the bus reset in this case. However, IEEE 1394a-2000 and IEEE 1394-2008 say that the bus manager may transmit a PHY configuration packet before a bus reset when correcting a gap count error. Since the standard endorses this, I decided it's safe to retain the PHY configuration packet transmission. Normally, after a topology change, we will reset the bus a maximum of 5 times to change the root node and perform gap count optimization. However, if there is a gap count inconsistency, we must always generate a bus reset. Otherwise the gap count inconsistency will persist and communication will be unreliable. For that reason, if there is a gap count inconstency, we generate a bus reset even if we already reached the 5 reset limit. Signed-off-by: Adam Goldman <adamg@pobox.com> Reference: https://sourceforge.net/p/linux1394/mailman/message/58727806/ Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2022-05-23Merge branch 'for-linus' into for-nextTakashi Iwai1-0/+3
Merge for 5.18-rc1 Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-04-25firewire: core: extend card->lock in fw_core_handle_bus_resetNiels Dossche1-0/+3
card->local_node and card->bm_retries are both always accessed under card->lock. fw_core_handle_bus_reset has a check whose condition depends on card->local_node and whose body writes to card->bm_retries. Both of these accesses are not under card->lock. Move the lock acquiring of card->lock to before this check such that these accesses do happen when card->lock is held. fw_destroy_nodes is called inside the check. Since fw_destroy_nodes already acquires card->lock inside its function body, move this out to the callsites of fw_destroy_nodes. Also add a comment to indicate which locking is necessary when calling fw_destroy_nodes. Cc: <stable@vger.kernel.org> Signed-off-by: Niels Dossche <dossche.niels@gmail.com> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20220409041243.603210-4-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-04-05firewire: add kernel API to access CYCLE_TIME registerTakashi Sakamoto1-0/+28
1394 OHCI specification defined Isochronous Cycle Timer Register to get value of CYCLE_TIME register defined by IEEE 1394 for CSR architecture defined by ISO/IEC 13213. Unit driver can calculate packet time by compute with the value of CYCLE_TIME and timeStamp field in descriptor of each isochronous and asynchronous context. The resolution of CYCLE_TIME is 49.576 MHz, while the one of timeStamp is 8,000 Hz. Current implementation of Linux FireWire subsystem allows the driver to get the value of CYCLE_TIMER CSR register by transaction service. The transaction service has overhead in regard of access to MMIO register. This commit adds kernel API for unit driver to access the register directly. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20220405072221.226217-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-04-05firewire: Add dummy read_csr/write_csr functionsHector Martin1-0/+11
(Hector Martin wrote) This fixes segfaults when a card gets yanked off of the PCIe bus while busy, e.g. with a userspace app trying to get the cycle time: [8638860.994310] Call Trace: [8638860.994313] ioctl_get_cycle_timer2+0x4f/0xd0 [firewire_core] [8638860.994323] fw_device_op_ioctl+0xae/0x150 [firewire_core] [8638860.994328] __x64_sys_ioctl+0x7d/0xb0 [8638860.994332] do_syscall_64+0x45/0x80 [8638860.994337] entry_SYSCALL_64_after_hwframe+0x44/0xae (Takashi Sakamoto wrote) As long as reading commit 20802224298c ("firewire: core: add forgotten dummy driver methods, remove unused ones"), three functions are not implemeted in dummy driver for reason; .read_csr, .write_csr, and .set_config_rom. In core of Linux FireWire subsystem, the callback of .set_config_rom is under acquisition of mutual exclusive for local list of card. The acquision is also done in process for removal of card, therefore it's safe for missing implementation of .set_config_rom. On the other hand, no lock primitive accompanies any call of .read_csr and .write_csr. For userspace client, check of node shutdown is done in the beginning of dispatch of ioctl request, while node shifts to shutdown state in workqueue context enough after card shifts to dummy driver. It's probable that these two functions are called for the dummy driver by the code of userspace client. In-kernel unit driver has similar situation. It's better to add implementation of the two functions for dummy driver. Signed-off-by: Hector Martin <marcan@marcan.st> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20220405072221.226217-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner1-14/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-24Merge tag 'firewire-updates' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394 Pull IEEE 1394 (FireWire) subsystem updates from Stefan Richter: - Fix mismatch between DMA mapping direction (was wrong) and DMA synchronization direction (was correct) of isochronous reception buffers of userspace drivers if vma-mapped for R/W access. For example, libdc1394 was affected. - more consistent retry stategy in device discovery/ rediscovery, and improved failure diagnostics - various small cleanups, e.g. use SCSI layer's DMA mapping API in firewire-sbp2 * tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394: firewire: sbp2: document the absence of alignment requirements firewire: sbp2: remove superfluous blk_queue_max_segment_size() call firewire: sbp2: use scsi_dma_(un)map firewire: sbp2: give correct DMA device to scsi framework firewire: core: fw_device_refresh(): clean up error handling firewire: core: log config rom reading errors firewire: core: log error in case of failed bus manager lock firewire: move rcode_string() to core firewire: core: improve reread_config_rom() interface firewire: core: wait for inaccessible devices after bus reset firewire: ohci: omit spinlock IRQ flags where possible firewire: ohci: correct signedness of a local variable firewire: core: fix DMA mapping direction firewire: use module_pci_driver
2012-05-09firewire: Move fw_card kref functions into linux/firewire.hChris Boot1-0/+1
When writing a firewire driver that doesn't deal with struct fw_device objects (e.g. it only publishes FireWire units and doesn't subscribe to them), you likely need to keep referenced to struct fw_card objects so that you can send messages to other nodes. This patch moves fw_card_put(), fw_card_get() and fw_card_release() into the public include/linux/firewire.h header instead of drivers/firewire/core.h, and adds EXPORT_SYMBOL_GPL(fw_card_release). The firewire-sbp-target module requires these so it can keep a reference to the fw_card object in order that it can fetch ORBs to execute and read/write related data and status information. Signed-off-by: Chris Boot <bootc@bootc.net> Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>