[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linux-ia64
Subject:    Re: KDB blindly reads keyboard port
From:       Bjorn Helgaas <bjorn.helgaas () hp ! com>
Date:       2006-11-16 16:28:01
Message-ID: 200611160928.02064.bjorn.helgaas () hp ! com
[Download RAW message or body]

On Wednesday 15 November 2006 21:02, Keith Owens wrote:
> I implemented this in my kdb tree, but it has a very nasty side effect,
> it stops you from debugging that part of the boot process between kdb
> startup and when the i8042 is probed.  KDB starts up very early so we
> can debug the boot process.  Not being able to use the PC keyboard
> until later in boot is not acceptable.  People using USB keyboards
> already suffer from this problem and it is very frustrating.
> 
> Adding a "kdb_use_keyboard" flag means all existing systems have to
> change if they want a debugger during boot, just to workaround a few
> systems that get an error when reading from non-existent legacy I/O
> ports.  So I am going back to my original idea, add 'kdb_skip_keyboard'
> which is only required on the problem machines.

Hold on a minute.  These "problem machines" are completely compliant
with all the relevant ia64 specs in this area.  There is no spec that
says a keyboard controller must be present or that reading a non-
existent I/O port should be safe.

What about the FADT iapc_boot_arch bit?  Did you determine that isn't
sufficient for some reason?  That's available very early.

Bjorn
-
To unsubscribe from this list: send the line "unsubscribe linux-ia64" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
[prev in list] [next in list] [prev in thread] [next in thread]