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A maintainer of Linux FireWire subsystem and ALSA firewire stack.
http://ieee1394.docs.kernel.org/
https://github.com/takaswie/linux-firewire-dkms/
takaswie

Takashi Sakamoto (坂本 貴史)

Edited 8 months ago
Posted: [GIT PULL] firewire updates for v6.11
https://lore.kernel.org/linux-kernel/20240720084730.GA59546@workstation.local/T/#u

There are many line changes for FireWire subsystem, while there is no
functional change for practical use. The most of changes are for code
refactoring, some KUnit tests to added helper functions, and new
tracepoints events for both the core functions and 1394 OHCI driver.

The tracepoints events now cover the verbose logging enabled by debug
parameter of firewire-ohci kernel module. The parameter would be removed
in any future timing, thus it is now deprecated.
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takaswie

Takashi Sakamoto (坂本 貴史)

Hm. I'm investigating to replace the local implementation to maintain blocks in the allocated memory region mapped for DMA purpose with common dma_pool. However, it does not allows to pick up an arbitrary count of blocks at once for continuous memory region. It just connect returned block to the tail of local list, and has no mechanism to keep maintained blocks as continuous.
Typically, this kind of framework requires mechanism to suppress fragmentation, but it has nothing. I prefer its simplicity, but a bit inconvenient for my purpose...
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takaswie

Takashi Sakamoto (坂本 貴史)

Being straightforward is not necessarily more adequate than being simple.
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takaswie

Takashi Sakamoto (坂本 貴史)

As I said.
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takaswie
repeated
lina@vt.social

Asahi Lina (朝日リナ) // nullptr::live

Figuring out how to represent this device's mixer controls in ALSA is pain peko...

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takaswie

Takashi Sakamoto (坂本 貴史)

Reply to @monsieuricon
@monsieuricon I sent it 14 June. I would appreciate any reaction to it.
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takaswie

Takashi Sakamoto (坂本 貴史)

Ah, indeed. PCI device driver has no need to know virtual address mapped to their DMA bus address, unless they have any interface to applications.
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takaswie

Takashi Sakamoto (坂本 貴史)

@monsieuricon It's time to redirect http://ieee1394.wiki.kernel.org/ to http://ieee1394.docs.kernel.org/, Would I request it to you?

https://lore.kernel.org/lkml/20240613090343.416198-1-o-takashi@sakamocchi.jp/
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takaswie

Takashi Sakamoto (坂本 貴史)

In a design of the core function, the device underlying the card is not necessarily 1394 OHCI, thus the identifier should not be selected from PCIe-related data. Hm.
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hrw@society.oftrolls.com

Marcin Juszkiewicz 🙃

Several websites write that snapdragon X devices are the first laptop with Arm cpu.

Acorn A4 was the first laptop with ARM cpu.

In June 1992. 32 years ago.

https://www.computinghistory.org.uk/det/22807/Acorn-A4-Laptop/

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takaswie

Takashi Sakamoto (坂本 貴史)

Alternatively, `card_index` or device major/minor numbers? An address in PCI bus?
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takaswie

Takashi Sakamoto (坂本 貴史)

Edited 9 months ago
Mmm. `__assign_str()` for` dev_name()` with `struct device *`. I don't like to put strings into data structure for tracepoints events...
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takaswie

Takashi Sakamoto (坂本 貴史)

wha...t...?
https://lore.kernel.org/lkml/000000000000100905061a18c63a@google.com/
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takaswie
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gregkh

Greg K-H

Reply to @joshbressers@infosec.exchange
@joshbressers @Di4na @kurtseifried The Linux kernel community has been using a LLM for many many years now to find security/bug-related fixes in order to flag them to be backported to stable kernels. Lots of papers were published on this, and presentations were made so you can point to lots of "prior art" here for anyone who wants to do this on their own.
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takaswie

Takashi Sakamoto (坂本 貴史)

I absolutely agree with this:
https://lore.kernel.org/lkml/ZkHKKvyLJSy8FYoU@gmail.com/
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takaswie

Takashi Sakamoto (坂本 貴史)

Edited 11 months ago
OHCI_TCODE_PHY_PACKET = TCODE_LINK_INTERNAL = OHCI1394_phy_tcode = 0xe in 1394 OHCI.
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takaswie

Takashi Sakamoto (坂本 貴史)

Reply to @gregkh
@gregkh Yup. I'm waiting for the release of -rc1 kernel to start the action.

I've been using the issued 1394 OHCI hardware in recent years to develop both Linux FireWire subsytem and IEC 61883-1/6 packet streaming engine in guest system to which the 1394 OHCI hardware is passedthough from host system. I have never experienced the reported issue.

In my opinion, the issue is in the PCIe host bridge or something like it in the reported Apple hardware which provides the secondary bus to the 1394 OHCI hardware. As long as I know, the reported Apple hardware has no IEEE 1394 interface, thus the patch author probably used some kind of specific hardware to connect the 1394 OHCI hardware. I guess that it should be [Apple thunderbolt display](https://lore.kernel.org/linux-pci/1372860295-8306-1-git-send-email-mika.westerberg@linux.intel.com/) or Apple thunderbolt 2 to FireWire adapter.

Anyway, it is better to ask the author what combination of hardware is used.
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takaswie

Takashi Sakamoto (坂本 貴史)

Edited 1 year ago

Hm. A commit 29a43dc130ce (“PCI: Mark LSI FW643 to avoid bus reset”) should be reverted, since it would include some misunderstandings.

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takaswie

Takashi Sakamoto (坂本 貴史)

Debian Bug report logs - #1061936 ITP: libhitaki -- Library to operate ALSA HwDep device for ALSA firewire stack
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1061936

Was closed!
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takaswie

Takashi Sakamoto (坂本 貴史)

Edited 1 year ago
[PATCH] firewire: ohci: suppress unexpected system reboot in AMD Ryzen machines and ASM108x/VT630x PCIe cards
https://lore.kernel.org/lkml/20231229035735.11127-1-o-takashi@sakamocchi.jp/
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