firewire: ohci: add tracepoints event for data of Self-ID DMA

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In 1394 OHCI, the SelfIDComplete event occurs when the hardware has
finished transmitting all of the self ID packets received during the bus
initialization process to the host memory by DMA.

This commit adds a tracepoints event for this event to trace the timing
and packet data of Self-ID DMA. It is the part of following tracepoints
events helpful to debug some events at bus reset; e.g. the issue addressed
at a commit d0b06dc48f ("firewire: core: use long bus reset on gap count
error")[1]:

* firewire_ohci:irqs
* firewire_ohci:self_id_complete
* firewire:bus_reset_handle
* firewire:self_id_sequence

They would be also helpful in the problem about invocation timing of
hardIRQ and process (workqueue) contexts. We can often see this kind of
problem with -rt kernel[2].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d0b06dc48fb1
[2] https://lore.kernel.org/linux-rt-users/YAwPoaUZ1gTD5y+k@hmbx/

Link: https://lore.kernel.org/r/20240702222034.1378764-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

...

This commit is contained in:

Takashi Sakamoto 2024-07-03 07:20:34 +09:00

parent 4a13617ef3

commit 526e21a2aa

2 changed files with 64 additions and 1 deletions

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11

drivers/firewire/ohci.c

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54

include/trace/events/firewire_ohci.h

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