Re: GEOM weirdness with SD flash reader?

From: Nate Lawson <nate_at_root.org>
Date: Sun, 01 Jul 2007 21:46:04 -0700
M. Warner Losh wrote:
> In message: <4688791D.6050007_at_root.org>
>             Nate Lawson <nate_at_root.org> writes:
> : What if we kicked off a thread to run every 3 seconds that did a quick
> : poll of such devices and sent a devd notify if they arrived (i.e. medium
> : present)?  It wouldn't work for floppy drives, but we could make this
> : part of the da driver or something in usermode like devd itself calling
> : camcontrol?
> 
> In the past, people have said that polling messes up multimedia
> access, so it hasn't happened.
> 
> But wouldn't a simple daemon in userland do the same thing?  Or
> parsing the output of camcontrol inquiry?  Camcontrol rescan is a nop
> for these devices.

camcontrol tur (test unit ready) will return an error or success if the
medium is now present.  Kicking off a process to do that when a
removable media da(4) device appears seems like a good idea.  It could
also be a thread in devd.

-- 
Nate
Received on Mon Jul 02 2007 - 02:46:12 UTC

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