public inbox for linux-acpi@vger.kernel.org
 help / color / mirror / Atom feed
From: "Michael H. Warfield" <mhw@WittsEnd.com>
To: Andrey Borzenkov <arvidjaar@mail.ru>
Cc: mhw@WittsEnd.com, linux-serial@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org
Subject: Re: 2.6.24: Serial disabled in BIOS but serial modules still loaded (probably PnP related)
Date: Sat, 24 Nov 2007 22:55:22 -0500	[thread overview]
Message-ID: <1195962922.5044.8.camel@canyon.wittsend.com> (raw)
In-Reply-To: <200711242336.43712.arvidjaar@mail.ru>

[-- Attachment #1: Type: text/plain, Size: 1557 bytes --]

On Sat, 2007-11-24 at 23:36 +0300, Andrey Borzenkov wrote:
> I have no COM port on notebook (without port replicator which I do not have)
> so COM is disabled in BIOS. No ttyS* is detected during boot (and no device
> created) but I just noticed that serial modules are still loaded. Well, this
> partially defeats the purpose of disabling COM port - the intention was to
> free resources by *not* loading unneeded modules ...

> This may have something to do with (ACPI) PnP which apparently believes COM is alive.
> Notebook is Toshiba Portege 4000.

	Nice...  What's this then?

> 00:09 PNP0501 16550A-compatible serial port
>     state = active
>         io 0x3f8-0x3ff
>         irq 5

	0x3f8-0x3ff is COM1 and a 16550A is the most common invocation of the
vernerable serial port.  I haven't seen a real 8250 in ages.  the 16550
is an 8250 with larger FIFO's and better rates.

	Now, it's on IRQ5 instead of IRQ4 but that's all allocatable on PCI.
Unless I'm missing something, it looks like you've got a COM port and it
looks like it's active.

	Might be related to an IR port?

> 00:0a SMCf010 SMC Fast Infrared Port
>     state = disabled

> 00:0b PNP0401 ECP printer port
>     state = disabled

	:

	Mike
-- 
Michael H. Warfield (AI4NB) | (770) 985-6132 |  mhw@WittsEnd.com
   /\/\|=mhw=|\/\/          | (678) 463-0932 |  http://www.wittsend.com/mhw/
   NIC whois: MHW9          | An optimist believes we live in the best of all
 PGP Key: 0xDF1DD471        | possible worlds.  A pessimist is sure of it!


[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 307 bytes --]

  parent reply	other threads:[~2007-11-25  4:25 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-24 20:36 2.6.24: Serial disabled in BIOS but serial modules still loaded (probably PnP related) Andrey Borzenkov
2007-11-24 23:09 ` Yinghai Lu
2007-11-25 16:50   ` Andrey Borzenkov
2007-11-25  3:55 ` Michael H. Warfield [this message]
2007-11-25  7:54   ` David Newall
     [not found] <fa.P01QcmUf2f3DN4etI8KJYFdaLnE@ifi.uio.no>
2007-11-25 18:39 ` Robert Hancock
2007-11-25 20:01   ` Andrey Borzenkov
2007-11-27  8:59     ` Shaohua Li

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1195962922.5044.8.camel@canyon.wittsend.com \
    --to=mhw@wittsend.com \
    --cc=arvidjaar@mail.ru \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox