From: Greg KH <greg@kroah.com>
To: linux-hotplug@vger.kernel.org
Subject: Re: Fwd: Fwd: How to determine which device crashes udev in boot?
Date: Thu, 17 Mar 2016 16:56:06 +0000 [thread overview]
Message-ID: <20160317165606.GA15807@kroah.com> (raw)
In-Reply-To: <CAD4SBxAoUczieAGCkjzMfYrPru4P+KJiVwA-TDkrdDS+osk_Lw@mail.gmail.com>
On Thu, Mar 17, 2016 at 05:54:10PM +0900, iwillallways forget1 wrote:
> Greg K-H replied to me:
> >> Some device has a working driver for Porteus's 64-bit kernel but a
> >> crashing driver for Porteus's 32-bit kernel, and the crash is so hard
> >> that it doesn't even start flashing two keyboard lights. Also this
> >> being text mode (when I type udevadm not startx), the crash is so hard
> >> that it doesn't print an oops.
> >
> > Use a serial console, that way you can see the oops happen there.
>
> Perhaps I should mention that I had
> tail -f /var/log/messages >/mnt/sdb1/what 2>&1 &
> running in the background before running udevd and udevadm trigger.
> The log included udev stuff until the crash, but did not include the oops.
Yes, that will not be saved as the kernel crashed.
> I think I own two USB-to-serial adapters and a serial reverse cable.
> I'll have to hunt for them and bring them to my employer.
> Do you think the oops will get out over a USB-to-serial adapter
> before the kernel crashes hard?
No, usb serial usually does not work for capturing oops messages because
the kernel crashes and USB needs interrupts to be running properly to
deliver data.
Try a "real" serial connection if the device has one.
As you know what kernel drivers are needed for this hardware (it works
in 64bit mode), just load them by hand, one by one, in 32bit mode and
see what one dies.
good luck,
greg k-h
prev parent reply other threads:[~2016-03-17 16:56 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-17 8:54 Fwd: Fwd: How to determine which device crashes udev in boot? iwillallways forget1
2016-03-17 16:56 ` Greg KH [this message]
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=20160317165606.GA15807@kroah.com \
--to=greg@kroah.com \
--cc=linux-hotplug@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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).