linux-embedded.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David VomLehn <dvomlehn-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
To: Andi Kleen <andi-Vw/NltI1exuRpAAqCnN02g@public.gmane.org>
Cc: Linux Kernel Mailing List
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Andrew Morton
	<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
	Linux Embedded Mailing List
	<linux-embedded-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Linux USB Mailing List
	<linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH] Wait for console to become available, v2
Date: Sun, 19 Apr 2009 09:23:36 -0700	[thread overview]
Message-ID: <49EB5008.1090000@cisco.com> (raw)
In-Reply-To: <874owlqcce.fsf-3rXA9MLqAseW/qJFnhkgxti2O/JbrIOy@public.gmane.org>

Andi Kleen wrote:
> VomLehn <dvomlehn-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org> writes:
>> History
>> v2	Wait for the preferred console rather than any console. Make the
>> 	delay interval a tunable.
> 
> CONFIG tunables are usually a bad idea. What should a binary distribution
> kernel set? Better make it a boot option with a reasonable default.

Your point about boot options is well taken; I released a more recent 
version of this patch with boot options last Friday and would appreciate 
your comments.

> Also a setting to panic in this case might be useful, normally a system
> without console is not very useful and needs to be rebooted anyways.

Umm, those of us in the embedded space have the, perhaps misguided, 
notion that our systems are quite useful without consoles...

But, more to the specific point, the console code is pretty smart. If 
you set your delay interval too short and the console comes up later, 
you won't see output to /dev/console, but you *will* see kernel printk 
output, including the message that no console could be opened. This 
would, hopefully, point the user to the problem. I can also make the 
message more specific about which parameter to set in that case.

> 
> -Andi


--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  parent reply	other threads:[~2009-04-19 16:23 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-16 19:08 [PATCH] Wait for console to become available, v2 VomLehn
2009-04-19  8:25 ` Andi Kleen
     [not found]   ` <874owlqcce.fsf-3rXA9MLqAseW/qJFnhkgxti2O/JbrIOy@public.gmane.org>
2009-04-19 16:23     ` David VomLehn [this message]
     [not found]       ` <49EB5008.1090000-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
2009-04-19 16:39         ` Andi Kleen
     [not found]           ` <20090419163923.GS14687-qrUzlfsMFqo/4alezvVtWx2eb7JE58TQ@public.gmane.org>
2009-04-19 23:17             ` David VomLehn

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=49EB5008.1090000@cisco.com \
    --to=dvomlehn-fyb4gu1cfyuavxtiumwx3w@public.gmane.org \
    --cc=akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org \
    --cc=andi-Vw/NltI1exuRpAAqCnN02g@public.gmane.org \
    --cc=linux-embedded-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.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;
as well as URLs for NNTP newsgroup(s).