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To: hosokawa@mt.cs.keio.ac.jp (HOSOKAWA Tatsumi)
cc: bde@freebsd.org, hackers@freebsd.org, bugs@freebsd.org, jmz@freebsd.org
Subject: Re: dev_attach after boot (Re: modloaded block/char device drivers) 
In-reply-to: Your message of "Thu, 21 Mar 1996 23:43:22 +0900."
             <199603211443.XAA08476@frig.mt.cs.keio.ac.jp> 
Date: Thu, 21 Mar 1996 10:09:35 -0800
From: Paul Traina <pst@shockwave.com>
Sender: owner-bugs@freebsd.org
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  Not all dynamic dev_attach() causes panic().
  
  For example,
  
  	if_ed	NE2000 compatible PCMCIA Ethernet	OK
  	if_nep	3C589x PCMCIA Ethernet			OK
  	if_fe	Fujitsu PCMCIA Ethernet			OK
  	wdc/wd	Flash ATA / Type 3 ATA disk		NG
  	sio	PCMCIA Modem				OK
  	aic/cd	SCSI CDROM w/ SlimSCSI PCMCIA		NG
  	aic/sd	SCSI HDD w/ SlimSCSI PCMCIA		NG
  
  So, I think adding the controllers dynamically causes this panic(),
  but I was confused by reading that qcam has the same problem.
  
  Apparently, qcam is not controller/disk type device.  Of course I read
  dev_attach() in kern_devconf.c and it seems to have no problem which
  causes such panic()'s.

No, but the one common thread is that all of the ones that are OK register
no character/block devices.