Re: Multiple functionality breakages in 2.6.12rc3 IDE layer

From: Bill Davidsen
Date: Thu Apr 28 2005 - 13:29:27 EST


On Thu, 28 Apr 2005, Alan Cox wrote:

> Ages ago we added an ide_default driver to clean up all the corner cases
> like spurious IRQs for a device with no matching driver (eg ide-cd and
> no CD driver) as well as ioctls and file access.
>
> 2.6.12rc removes it. Unfortunately it also means that if your only IDE
> interface is one you hand configure you can no longer run Linux. It also
> changes other aspects of behaviour although they don't look problematic
> for most users. You can no longer
> - Control the bus state of an interface
> - Reset an interface

But isn't that the stuff we use for swapping drives? Down the drive, down
the interface, swap, and restart? Are these the functions called by hdparm
(-bRU) which are all of a sudden not going to work? Or am I being
alarmist?

> - Add an interface if none exist
> - Issue raw commands
> - Get an objects bios geometry
> - Read the identify data by ioctl (its still in proc but may be stale)
>
> without having a device specific driver loaded matching the media - and
> that only works if its already detected the device correctly.

I missed the discussion of why it was felt that the users would no longer
want to be able to do these things, or the new way to do it.
>
> I don't have the tools at the moment to generate spurious IRQ's for
> devices with no driver loaded but it does look like the code may well
> then crash. From the way the changes were done it appears the current
> IDE maintainers never appreciated that ide_default existed for far more
> than just cleaning up ide-proc but also to handle IRQ's, opening of
> empty slots, ioctls and power
> management ?
>
I suspect that's true, but should it not have been discussed first?

> The ability to specify the IDE ports on the command line as needed for
> some Sony laptop installs have also become "obsolete" over time. They
> still appear to work but spew a warning that the user will soon be
> screwed.

I'll have to read the release notes and see who to thank for this
reduction in functionality.

--
bill davidsen <davidsen@xxxxxxx>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.

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