kernel/linux.git/drivers/firewire/core.h, branch v6.18.21

firewire: core: fix undefined reference error in ARM EABI

2025-09-28T01:20:30+00:00

For ARM EABI, GCC generates a reference to __aeabi_uldivmod when compiling a division of 64-bit integer with 32-bit integer. This function is not available in Linux kernel. In such cases, helper macros are defined in include/linux/math64.h. This commit replaces the division with div_u64(). Fixes: 8ec6a8ec23b9 ("firewire: core: suppress overflow warning when computing jiffies from isochronous cycle") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202509270428.FZaO2PPq-lkp@intel.com/ Link: https://lore.kernel.org/r/20250928011910.581475-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto

firewire: core: suppress overflow warning when computing jiffies from isochronous cycle

2025-09-24T13:19:15+00:00

The multiplication by USEC_PER_SEC (=1000000L) may trigger an overflow warning with 32 bit storage. In the case of the subsystem the input value ranges between 800 and 16000, thus the result always fits within 32 bit storage. This commit suppresses the warning by using widening conversion to 64 bit storage before multiplication, then using narrowing conversion to 32 bit storage. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202509170136.b5ZHaNAV-lkp@intel.com/ Fixes: 379b870c28c6 ("firewire: core: use helper macros instead of direct access to HZ") Link: https://lore.kernel.org/r/20250924131140.261686-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto

firewire: core: use helper macros instead of direct access to HZ

2025-09-15T02:49:34+00:00

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

firewire: core: use macro expression for not-registered state of BUS_MANAGER_ID

2025-09-13T10:59:21+00:00

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

firewire: core: use macro expression for gap count mismatch

2025-09-13T10:59:21+00:00

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

firewire: core: add helper functions to access to fw_device data in fw_node structure

2025-09-08T01:26:26+00:00

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

firewire: Correct some typos

2024-10-01T10:02:57+00:00

Fixed some confusing typos that were currently identified with codespell, the details are as follows: drivers/firewire/core-topology.c:59: containted ==> contained drivers/firewire/core.h:83: reenable ==> re-enable drivers/firewire/ohci.c:1387: apppends ==> appends drivers/firewire/ohci.c:2216: superceded ==> superseded drivers/firewire/ohci.c:2617: litte ==> little Signed-off-by: Shen Lichuan Link: https://lore.kernel.org/r/20240930023344.7535-1-shenlichuan@vivo.com Signed-off-by: Takashi Sakamoto

Revert "firewire: core: move workqueue handler from 1394 OHCI driver to core function"

2024-09-12T13:30:35+00:00

This reverts commit 767bfb9ef27ebf760290d9f8bc303828b018c312. It appears that the call of ohci_flush_iso_completions() in the work item scheduled by hardIRQ of 1394 OHCI for any isochronous context changes the timing to queue events in the view of user space application. Link: https://lore.kernel.org/r/20240912133038.238786-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto

firewire: core: move workqueue handler from 1394 OHCI driver to core function

2024-09-09T14:00:17+00:00

In current implementation, the work item for isochronous context executes the same procedure of fw_iso_context_flush_completions() internally. There is a space to refactor the implementation. This commit calls fw_iso_context_flush_completions() in the work item. It obsoletes fw_iso_context_init_work(). It also obsoletes a pair of disable_work_sync() and enable_work() since the usage of test_and_set_bit_lock() mediates concurrent call already. Link: https://lore.kernel.org/r/20240909140018.65289-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto

firewire: core: expose kernel API to schedule work item to process isochronous context

2024-09-08T04:05:48+00:00

In packet-per-buffer mode for isochronous context of 1394 OHCI, software can schedule hardIRQ to the buffer in which the content of isochronous packet is processed. The actual behaviour is different between isochronous receive (IR) and transmit (IT) contexts in respect to isochronous cycle in which the hardIRQ occurs. In IR context, the hardIRQ occurs when the buffer is filled actually by the content of received packet. If there are any isochronous cycles in which the packet transmission is skipped, it is postponed to generate the hardIRQ in respect to the isochronous cycle. In IT context, software can schedule the content of packet every isochronous cycle including skipping, therefore the hardIRQ occurs in the isochronous cycle to which the software scheduled. ALSA firewire stack uses the packet-per-buffer mode for both IR/IT contexts. To process time stamp per packet (or per sample in some cases) steadily for media clock recovery against unexpected transmission skips, it uses an IT context to operate all of isochronous contexts by calls of fw_iso_context_flush_completions() in the bottom-half of hardIRQ for the IT context. Although it looks well to handle all of isochronous contexts in a single bottom-half context, it relatively takes longer time. In the future code integration (not yet), it is possible to apply parallelism method to process these context. In the case, it is useful to allow unit drivers to schedule work items to process these isochronous contexts. As a preparation, this commit exposes fw_iso_context_schedule_flush_completions() as a kernel API available by unit drivers. It is renamed from fw_iso_context_queue_work() since it is a counter part of fw_iso_context_flush_completions(). Link: https://lore.kernel.org/r/20240908040549.75304-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto