Re: console issue since 3.6, console=ttyS1 hangs

From: Peter Hurley <peter@hurleysoftware.com>
To: Nathan Zimmer <nzimmer@sgi.com>
Cc: Sean Young <sean@mess.org>,
	Linux kernel mailing list <linux-kernel@vger.kernel.org>,
	"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Alan Cox <alan@linux.intel.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Subject: Re: console issue since 3.6, console=ttyS1 hangs
Date: Thu, 3 Nov 2016 18:25:46 -0600	[thread overview]
Message-ID: <CAKU3ayVEsv0Qpk7AU9NwbAX5nOBkHVaj0SA2QnYFuHCQSWjv7A@mail.gmail.com> (raw)
In-Reply-To: <20161102152951.GA107664@stormcage.americas.sgi.com>

On Wed, Nov 2, 2016 at 9:29 AM, Nathan Zimmer <nzimmer@sgi.com> wrote:
> On Mon, Oct 31, 2016 at 08:55:49PM -0600, Peter Hurley wrote:
>> On Mon, Oct 31, 2016 at 2:27 PM, Sean Young <sean@mess.org> wrote:
>> > On Sun, Oct 30, 2016 at 10:33:02AM -0500, Nathan wrote:
>> >> I think this should be PNP0501 instead of PNP0c02.
>> >> Once I alter that then when I boot the serial comes up on irq 3. However it
>> >> still hangs.
>> >> I'll keep digging.
>> >
>> > Well that's that theory out of the window. I'm not sure where to look now,
>> > I would start by enabling as many as possible of the "kernel hacking" config
>> > options and see if anything gets caught.
>> >
>> > Looking at your earlier messages, you have a collection of percpu allocation
>> > failures. That might be worth resolving before anything else.
>>
>> Hi Nathan,
>>
>> Couple of questions:
>> 1. Was login over serial console setup and working on SLES 11?  or was
>> the 'console=ttyS1' only for debug output?
>> I ask because console output doesn't use IRQs; iow, maybe the serial
>> port w/ driver never actually worked.
>> 2. Can you post dmesg for the SLES 11 setup?  That would show if there
>> were probe errors even on that.
>>
>> An alternative that should be equivalent to your previous setup is to
>> build w/ CONFIG_SERIAL_8250_PNP=n
>> Seems like your ACPI BIOS is buggy, but also that something else is using IRQ 3?
>>
>> Regards,
>> Peter Hurley
>
>
>
> 1) Yes I can confirm I used it to login sometimes.
>
> I built with CONFIG_SERIAL_8250_PNP=n and that seemed to work better, in that the system did not hang.
> However I couldn't login on the serial and got these error messages, I suspect I broke something while trying different permutations.
>
> gdm[5206]: WARNING: GdmDisplay: display lasted 0.136636 seconds
> gdm[5206]: WARNING: GdmDisplay: display lasted 0.180955 seconds
> gdm[5206]: WARNING: GdmDisplay: display lasted 0.161415 seconds
> gdm[5206]: WARNING: GdmLocalDisplayFactory: maximum number of X display failures reached: check X server log for errors
>
> It did boot all the way though.
>
> 2) attached log

So I'm confused where this leaves us.

In your OP, you claim to have gotten it working with a partial revert
of commit 835d844d1a28 (but you didn't attach the partial revert so no
one knows what you did); however, my suggestion should have been
equivalent.

Note that you have the serial port disabled in BIOS; that's why you're
getting the probe error for PNP.

Regards,
Peter Hurley