From: Keith Owens <kaos@sgi.com>
To: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: Re: KDB blindly reads keyboard port
Date: Fri, 10 Nov 2006 15:23:20 +1100 [thread overview]
Message-ID: <14134.1163132600@kao2.melbourne.sgi.com> (raw)
In-Reply-To: Your message of "Tue, 26 Sep 2006 13:54:30 CST." <200609261354.30722.bjorn.helgaas@hp.com>
Bjorn Helgaas (on Tue, 26 Sep 2006 13:54:30 -0600) wrote:
>get_kbd_char() in arch/ia64/kdb/kdba_io.c does "inb(KBD_STATUS_REG)".
>
>But we don't know whether there's even an i8042 keyboard controller
>present. On HP ia64 boxes, there is no i8042, and trying to read
>from it can cause an MCA.
>
>This depends on the specific platform and how it is configured. I
>observed this MCA while booting the SLES10 install kernel on an
>HP rx7620 in "default" acpiconfig mode. The supported acpiconfig
>mode on this box is "single-pci-domain", which also puts some
>legacy ports into "soft-fail" mode, where the read will just return
>0xff instead of causing an MCA. But I think it's wrong to blindly
>poke around in I/O port space.
Bjron, could you try kdb-v4.4-2.6.19-rc5-{common,ia64}-2 on your
problem system? I changed kdb so it only uses the keyboard if at least
one console matches the pattern /^tty[0-9]*$/. IOW, if the user
specifies an i8042 style console on the command line (or uses the
default with CONFIG_VT=y) then kdb will attempt to use that keyboard.
Otherwise kdb ignores a VT style console, even when the kernel is
compiled with CONFIG_VT=y.
next prev parent reply other threads:[~2006-11-10 4:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-26 19:54 KDB blindly reads keyboard port Bjorn Helgaas
2006-09-27 2:45 ` Keith Owens
2006-09-27 11:57 ` Matthew Wilcox
2006-09-27 22:11 ` Bjorn Helgaas
2006-09-29 2:18 ` Keith Owens
2006-09-29 16:57 ` Bjorn Helgaas
2006-09-29 18:01 ` Luck, Tony
2006-09-29 18:58 ` Bjorn Helgaas
2006-11-16 4:02 ` Keith Owens
2006-11-16 16:28 ` Bjorn Helgaas
2006-11-10 4:23 ` Keith Owens [this message]
2006-11-10 4:28 ` Matthew Wilcox
2006-11-10 6:15 ` Keith Owens
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