Re: Hotplug *seems* to hang during boot]

[Dave Dodge <dododge@dododge.net>]

On Mon, Oct 04, 2004 at 07:14:07PM +0000, Richard Wild wrote:
> Some other information noticed: it seems (to me) quite likely that the 
> message "cardmgr[953]: no sockets found!" is related to the problem, 
> because when I boot the 2.4 kernel is says instead "cardmgr[80]: no 
> pcmcia driver in /proc/devices".

cardmgr is a bit strange in how it accesses devices.  Here's a quick
explanation in case it's relevant to the problem.

"no pcmcia driver in /proc/devices":

That means just what it says.  cardmgr wants the major device number for
the pcmcia driver, so it reads through /proc/devices looking for it.
This error message indicates that it did not find a "pcmcia" line,
presumably because no driver was loaded.

"no sockets found!":

This indicates that it _did_ find "pcmcia" listed in /proc/devices,
and it tried to access the driver.  Here's where things get a bit
unusual.  After obtaining the major device number from /proc/devices,
cardmgr uses mknod(2) to create device files of its own.  It starts
with minor device 0 and continues in a one-up loop until it fails.
For each minor number, it creates a device file with a name of the
form "cm-PID-COUNTER", opens the file, and then immediately unlinks
the file while holding it open.  There are a number of directories
where it might try to do this, usually in this order:

  /var/lib/pcmcia, /var/run, /dev, /tmp

The "no sockets found" message indicates that it managed to do the
mknod for minor device 0, but got an ENODEV when it then tried to open
the resulting file.

So what this seems to be saying is that:

  - your 2.4 kernel has no PCMCIA stuff loaded at all.

  - your 2.6 kernel has at least the "ds" driver, which
    creates the "pcmcia" /proc/devices entry, but it has no
    card sockets.

I don't know if this is part of your problem or not, but since cardmgr
does do some device file manipulation, it might be worth investigating.

                                                  -Dave Dodge


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