linux-toradex.git/drivers/firewire, branch v6.12-rc1

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

  At -rc1 we'll need do a mechanical removal of no_llseek -

  git grep -l -w no_llseek | grep -v porting.rst | while read i; do
	sed -i '/\/d' $i
  done

  would do it.

Unfortunately, that hadn't been done.  Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
	.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

firewire: core: rename cause flag of tracepoints event

2024-09-12T13:30:38+00:00

The flag of FW_ISO_CONTEXT_COMPLETIONS_CAUSE_IRQ directly causes hardIRQ
request by 1394 OHCI hardware when the corresponding isochronous packet is
transferred, however it is not so directly associated to hardIRQ
processing itself.

This commit renames the flag so that it relates to interrupt parameter of
internal packet data.

Link: https://lore.kernel.org/r/20240912133038.238786-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: core: update documentation of kernel APIs for flushing completions

2024-09-12T13:30:37+00:00

There is a slight difference between fw_iso_context_flush_completions() and
fw_iso_context_schedule_flush_completions().

This commit updates the documentations for them.

Link: https://lore.kernel.org/r/20240912133038.238786-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: core: add helper function to retire descriptors

2024-09-12T13:30:36+00:00

Both IR/IT contexts use the same code to retire completed descriptors
as AT context uses.

This commit adds a helper function to reduce the duplicated codes.

Link: https://lore.kernel.org/r/20240912133038.238786-4-o-takashi@sakamocchi.jp
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

Revert "firewire: core: use mutex to coordinate concurrent calls to flush completions"

2024-09-12T13:30:34+00:00

This reverts commit d9605d67562505e27dcc0f71af418118d3db91e5, since this
commit is on the following reverted changes.

Link: https://lore.kernel.org/r/20240912133038.238786-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: core: use mutex to coordinate concurrent calls to flush completions

2024-09-09T14:00:18+00:00

In current implementation, test_and_set_bit_lock() is used to mediate
concurrent calls of ohci_flush_iso_completions(). However, the ad-hoc
usage of atomic operations is not preferable.

This commit uses mutex_trylock() as the similar operations. The core
function is responsible for the mediation, instead of 1394 OHCI driver.

Link: https://lore.kernel.org/r/20240909140018.65289-3-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: fulfill documentation of fw_iso_context_flush_completions()

2024-09-08T04:05:49+00:00

The fw_iso_context_flush_completions() is the counterpart of
fw_iso_context_schedule_work() to process isochronous context in current
process context.

This commit fulfills its documentation.

Link: https://lore.kernel.org/r/20240908040549.75304-3-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