Re: mesh SCSI bus locks hard on 7500 when burning a CD-R in dao mode

On Tue, Jan 30, 2001 at 10:28:25PM +0100, Michael Schmitz [off-list ref] wrote:

The big question: why does this particular command time out in the first
place? Does the target expect more data to be sent? Does the target just
crash and fails to release the bus? It seems to work on other host
adapters, doesn't it?

There's a report of excatly the same failure mode on mac53c94 with a
different brand (Sony, as opposed to Yamaha on my MESH) of DVD drive.
So the only points in common seem to be that the DVD drives are running
on mac hardware and that the drivers are written by Paul Mackerras.  :-)
I don't at all mean to impugn Paul's coding ability, which is obviously
excellent, but the fact that he wrote both the drivers may mean that
they share lots of code and possibly share the same bug.

-Daniel

--
Daniel E. Eisenbud
eisenbud@cs.swarthmore.edu

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quoted

The big question: why does this particular command time out in the first
place? Does the target expect more data to be sent? Does the target just
crash and fails to release the bus? It seems to work on other host
adapters, doesn't it?

There's a report of excatly the same failure mode on mac53c94 with a
different brand (Sony, as opposed to Yamaha on my MESH) of DVD drive.

Please send a detailed description on how to reproduce this bug by PM.
I'll try to look into that on my Lombard, and in case I can get the
required binaries for m68k I'd also test on an old Quadra with 53c9x
SCSI.

Does the bug happen only with DVD writers, or regular CD writers?

So the only points in common seem to be that the DVD drives are running
on mac hardware and that the drivers are written by Paul Mackerras.  :-)
I don't at all mean to impugn Paul's coding ability, which is obviously
excellent, but the fact that he wrote both the drivers may mean that
they share lots of code and possibly share the same bug.

If so, the bug should have propagated to the m68k 53c9x driver. Wouldn't
be the 53c9x first weirdness - I never got it to accept a DAT drive (old
DDS-1, possibly Apple) without blowing up.

It might be something PPC specific as well and have nothing to do with
Paul's drivers.

	Michael


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On Tue, 30 Jan 2001, Michael Schmitz wrote:

quoted

So the only points in common seem to be that the DVD drives are running
on mac hardware and that the drivers are written by Paul Mackerras.  :-)
I don't at all mean to impugn Paul's coding ability, which is obviously
excellent, but the fact that he wrote both the drivers may mean that
they share lots of code and possibly share the same bug.

If so, the bug should have propagated to the m68k 53c9x driver. Wouldn't
be the 53c9x first weirdness - I never got it to accept a DAT drive (old
DDS-1, possibly Apple) without blowing up.

FYI, my DDS-1 worked with my MESH. Not perfectly, sometimes it gave a warning
(lost arbitration, IIRC), which aborted the current reading/writing.

Moving the DD-1 to the Sym53c875 solved the problem.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds


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