Due to present circumstances I need to ask all of you for help: did anyone have contact with Jean-Francois Bachelet (Voxel) during the last weeks?

If so, please let me know by mail on mboehmer@e3b.de - my mails and letters (even registered ones) stay unanswered. A valid phone number is not known to me.

Thanks in advance, Michael

@Rogue

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I'm doing hardware, so I must beg your pardon for my simplified view of the world. In hardware, you always are limited in number of registers, and number of logic resources, and maybe even the design of the DMA engine inside the I/O chip you have.

Nowadays, and in case of the Deneb, this doesn't matter, as the bus controller FPGA is only filled to a certain percentage, and I have loads of resources free for upgrades and workarounds, but for all existing hardware on Zorro III doing DMA these limitations mentioned above do exist.

If you take a device driver of OS3.x doing DMA, or any application which does reserve DMA buffers under OS3.x, then it will use the AllocVec() function or its equivalent.
This does deliver a physically continous segment of memory which can be used for DMA.

Under OS4 this behaviour has been changed, whether this is intended or not.

But: taken the case that the most popular DMA devices on Amiga Classic won't receive any updates to provide them with a scatter/gather DMA engine (in most cases this can't be done, as resources in the chips are too small), then the small change in memory allocation did KILL all those devices for OS4. Simple as that.

This includes the A4000T onboard SCSI, the Fastlane SCSI and the A4091 (latter one broken by design in DMA anyhow).

Of course you may still workaround this situation (which was a feature?) by limiting DMA transfers to 4KB, AFAIK this is the smallest memory segment under OS4. But then you drop performance, as each 4KB block will need its own DMA engine setup, CachePreDMA(), interrupt, CachePostDMA() and all administration stuff correlated to DMA.

And yes, I consider this particular detail in OS4 as broken.

Michael

@Spirantho

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Don't take this too serious
Thanks for the flowers regarding delivery! Hope we can keep our promises regarding the Deneb.

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Well, at least the preseries card here runs under JIT in AOS4 Classic on my machine with the latest versions of Poseidon (3.8r2 und up), so I would assume the series cards will work the same way.

BUT: we don't have any developper information on OS4, and as the driver runs under JIT (which introduces additional delays maybe), we cannot guarantee operation. Simply as that.

To our best knowledge operation in Zorro II/III PIO mode of the Deneb in AOS4 is possible.

Ah, yes, your last question: there is no upgrade path for users of our "old" USB boards, no "Trade-In" program and for sure no "Free Shipment due to whatsoever just happened outside our kitchen window" action.

Michael

@Spirantho

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I have a setup of A4000T + HIGHWAY running here flawless.

But: if Poseidon + OS3.9 + HIGHWAY work fine, while Sirion + OS4.0 + HIGHWAY do some bad things, then I must assume that there might be a bug inside the Sirion Highway driver. From what you tell here I would bet on a buig inside the interrupt handling.
We have loads of HIGHWAYs out at users for years now, and noone reported such a bug up to now.

I never noticed such behaviour as you described here.

Please report this failure to the AOS4 team, they may be able to reproduce it and maybe fix it.

Michael

@Spirantho

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Erm. I try not to take this as an offense

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I'm open for people willing to do an AOS4 Classic driver for the Deneb. Documentation for this task can be provided, with NDA on it, as lot of work did go into implementing the Deneb DMA engine into the FPGA, and I see a need for protecting this IP of mine.
There may even be more work coming up for upgrading the DMA engine with Scatter/Gather support to workaround the current situation where only DMA transfers with 2kB can be done (Deneb DMA engine can do 64kB at once, limited by onchip buffers in the USB host controller).

Under OS3.x this is not needed.

Nevertheless the Deneb works already under AOS4 in PIO mode (as stated by other people in this thread, DMA and memory allocation is kind of broken in OS4).

Michael

P.S.: For me it's the other way round - Sirion under OS4 Classic is not good enough for me, being used to work with Poseidon