Re: [git pull] New firewire stack

From: Jonathan Woithe
Date: Thu May 03 2007 - 19:08:26 EST


> Jonathan Woithe wrote:
> >> Olaf Hering wrote:
> >>> NACK.
> >>> Upgrade the current drivers/ieee1394/ with the new code, and keep all
> >>> existing module names.
> [...]
> > However, as a compromise how about renaming the existing stack's modules and
> > then reusing the existing names for the new stack? Messy I know, but this
> > way both stacks would still be available without recompilation for those who
> > needed them and the sbp2-as-root dilemma raised by Olaf would also be
> > covered.
>
> I.e. new modules:
> ieee1394 (was fw-core)
> ohci1394 (was fw-ohci)
> :

> old modules, for example:
> ieee1394-old
> ohci1394-old
> :
>
> Looks... weird.
>
> On the other hand, a 1394 module compilation cycle in order to do the
> fallback is not such a huge issue, except that it requires the person to
> be able to compile modules. That's probably the main issue.

True on all counts. I guess it's a question of whether the lack of an easy
fallback path will significantly reduce the number of testers. I don't have
enough of a feel to answer that.

> eth1394 (to be done) --- but that's a bad name anyway, it
> implements IP over 1394, not Ethernet

So, when eth1394 is ported the name should be something like fw-ip, at least
if we are to remain consistent with the other 3 module names.

> > Oh yes, it would be nice to have working PCILynx support again (although I
> > acknowledge it's unlikely to happen). Some of us do have these cards
> > installed for sniffing purposes (using nosy) but it would be nice to be able
> > to use them with libraw1394 as well. It would for example save me having to
> > swap cards depending on what I needed to do (I have insufficient PCI slots
> > to have both the PCILynx and OHCI cards installed simultaneously).
>
> But then, what is the actual utility of pcilynx? (I mean the current
> driver, not the card or a future driver.) Last time I checked, sbp2 was
> broken without OHCI's physical DMA, and AFAIK raw1394's newer iso API
> and video1394 and dv1394 don't work with pcilynx either.

It certainly doesn't support the raw1394 API so its current usefulness is
extremely limited.

> Porting pcilynx to the new low-level API would be quite resource
> demanding --- seen in relation to which resources we have, what the
> existing pcilynx driver's state of affairs is, and how rare the hardware
> is. (For those who have the hardware, the stand-alone Nosy is
> undoubtedly the killer application, not pcilynx.)

Precisely. As I said, I've probably got a corner case and it's certainly
not worth the effort just for that. It would be nice though. You're right
about nosy; so long as nosy (which is independent of the firewire stack)
keeps working I'll be happy. :)

Regards
jonathan
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