Using a custom DSDT with Fedora

[Peter Jones]

On Mon, 2006-10-09 at 11:10 -0400, David Zeuthen wrote:

> Reading the whole thread I think we need to fix a few things in Fedora
> though. Here's an example where Richard actually fixed a bug. Can anyone
> explain why Richard needs to jump through hoops to actually apply his
> bug fix? Clearly something is broken with Fedora here.

What he's asking for _isn't_ "applying a fix".  That would be flashing
his firmware so it uses the new DSDT.

> At the very least we ought to provide the option to mkinitrd so it can
> include the new DSDT and load it into the kernel at startup. IIRC the
> main resistance is that upstream kernel and other developers don't like
> to deal with bug reports when a custom DSDT is used. So perhaps one way
> of dealing with this is to taint the kernel if that isn't happening
> already.
> 
> I also think we need to think about the experience we want people to
> have when they use Fedora. We already have thousands of work arounds and
> quirks for broken hardware in Fedora, why doesn't this apply to the
> DSDT? Just because it's firmware? What are the risks here? What are the
> main issues Fedora developers have here?

"I'm using my own system firmware" is one more piece of data that'll
pretty much always get left out of bug reports.  And tainting solves
that _if_ the error is a kernel traceback, but if it's bad values
in /proc/acpi/battery/BAT0/info and g-p-m misbehaving because of it,
there will be no evidence of what's going on.  We already get enough
bogus bug reports.

Obviously, the user in this scenario isn't Richard -- but it probably is
90% of the people who would want to do this.

If people have system firmware bugs, they need to work with their system
vendor to fix their system firmware.

> In other words: Why can't we ship updated DSDT tables if the vendor
> (Lenovo in this case) have ACK'ed the DSDT with the bug fix and said
> it's the right update? (maybe there are redistribution issues here)

If the vendor has ACKed it, why wouldn't there be a firmware update to
actually fix the problem?

> Further, if a vendor has an updated BIOS and it's suitable for
> redistribution in Fedora, why can't we include that BIOS image and ask
> the user if he wants to flash his BIOS?

That (or something like Dell's yum repo based firmware update system)
might be plausible, but it's orthogonal to being able to load a custom
DSDT.

-- 
  Peter