Re: Problems with Adaptec 2940 as a module

Michael K. Johnson (johnsonm@redhat.com)
Mon, 21 Oct 1996 16:15:03 -0400


Rob Coleman writes:
>I have just recently taken my core file systems off of my SCSI drive,
>and would like to modularize both the SCSI high- and mid-level drivers,
>in addition to the low-level driver. If I modularize everything, when I
>try to access a scsi device, the high- and mid-level drivers get loaded,
>but the low-level driver is not. This makes the system believe that the
>system supports SCSI, but doesn't have any devices. If I load the
>aic7xxx.o module, it loads and initializes the driver and everything
>works fine. So, it would be nice if the high-level driver could get
>this loaded automatically.

I think that this bug is fairly generic. Here at Red Hat, we've had
reports that moving from modularized low-level SCSI drivers to drivers
compiled into the kernel has fixed the exact same problem (the card
being found, but no devices being found on the bus) for people with
aha174x's and DPT's using the eata_dma driver. I'm currently looking
into ncr53c8xx (the driver that appeared not to work is Drew's, not
Gerard's) and various aic7xxx controllers. Others I'm not sure about;
the Advansys driver *might* be exhibiting the same problem, but the
bug reports aren't clear in this case.

I get the impression that with the aic7xxx, it at least sometimes
works as a module, but I've heard at least one report from someone
else that one card (I think a 3940) which did not work with a module
did work with a compiled-in driver. There may be issues like the
amount of RAM involved, but I haven't seen a pattern yet.

It shows up a little more spectacularly with Red Hat Linux 4.0
because we use initrd and SCSI modules to have a single boot
image for everyone. Unfortunately, it took a while to track
down, because at least some of these drivers appeared to work
for some people and not others, and we're still working on getting
more information. But I think we've got enough information at this
point to indicate that this isn't a red herring.

Any guesses as to the cause?

michaelkjohnson

"Ever wonder why the SAME PEOPLE make up ALL the conspiracy theories?"