Re: Problems with Adaptec 2940 as a module

Rob Coleman (rcoleman@cc.gatech.edu)
Tue, 22 Oct 1996 00:41:14 -0400 (EDT)

- 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.

I fixed some of the problem that I was having by adding a line in
modules.conf that loads the low-level driver when the major number of
the SCSI driver is accessed. The default is to load sd_mod (?), but
changing that to the low-level driver (in this case, aic7xxx.o)
implicitly loads sd_mod. This allows me to access my tape drive, but
not my hard drive. Both are detected, but I am not able to mount my
hard drive afterward. I believe that the error was something like
"Device not available."

-- 
Rob Coleman               Georgia Tech            rcoleman@cc.gatech.edu