Re: No IDE drivers loaded for Toshiba Satellite 320 CDS

From: Tejun Heo
Date: Tue Apr 15 2008 - 19:31:49 EST


Hi,

Lennart Sorensen wrote:
Yes. After all you would quickly see a problem if you built a kernel
with all the IDE drivers built in, which some people do. In that case
ide generic is always activated last and anything bad that would happen
with loading a module would happen built in too.

Yeah, pick the right configuration. You can make it malfunction.

I think it is the wrong place to worry about problems. If a native
driver takes control of a chip, it is that drivers responsibility to
reserve any relevant ports on that chip sufficiently to prevent another
driver from messing with it that doesn't know anything about that chip.
If the native driver doesn't load at all, then ide-generic ought to try
and drive the chip if it has legacy ports.

I'm not too sure whether that will be always possible and I'm less sure we'll get enough test coverage over this kind of stuff.

So my opinion is that making life easy to those machines with legacy ide
ports is a good thing, while trying to be overly paranoid about one
driver potentially hitting a bug in another driver is just silly. Why
couldn't two native ide drivers potentially go looking for the same
ports too? Are you sure no native driver uses the legacy IDE port
numbers to control a chip in native mode? Finding bugs is good since
then they can be fixed. Trying to prevent hitting bugs (which shouldn't
be there in the first place) doesn't seem useful.

Yeah, theoretically, you're right. The problem is that what breaks when things go wrong. If you don't probe generic ports by default, harddisks won't be detected on some legacy systems but you can always prompt the user about loading the generic driver. If you probe generic ports by default, when things go wrong, you break modern machines in an unrecoverable (w/o reset) way. I'd rather choose bothering the user on legacy machines.

thanks.

--
tejun
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