Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 23 Jul 2009 11:33:38 -0400
From:      "Peter C. Lai" <peter@simons-rock.edu>
To:        Andriy Gapon <avg@icyb.net.ua>
Cc:        Sagara Wijetunga <sagara@tomahawk.com.sg>, Eugene Grosbein <eugen@kuzbass.ru>, freebsd-stable@freebsd.org
Subject:   Re: SCSI device not created upon a CF card plug in
Message-ID:  <20090723153338.GA31463@cesium.hyperfine.info>
In-Reply-To: <4A6880A1.3010003@icyb.net.ua>
References:  <20090723055317.GA72627@svzserv.kemerovo.su> <20090723141440.A69EF1CC0B@ptavv.es.net> <4A6880A1.3010003@icyb.net.ua>

next in thread | previous in thread | raw e-mail | index | archive | help
GEOM should pick up the state change, but the bug may continue to exist
because the CF reader is tagged as a storage device with invalid media
when umass attaches to it on startup; there wasn't a really good way to
actually enumerate the slice table upon insertion because the device
does not send a disconnect/reconnect to the bus when you insert the
card. At the time, the workaround was to tickle the device by attempting
a mount against the whole disk, then the slice table will be enumerated.

Example, CF card reader on boot will be picked up as /dev/da4
You insert card, no state change can be detected because the device
doesn't get reset on the bus.
mount /dev/da0 /mnt <-- will fail for obvious reasons, but now slices
are enumerated
mount /dev/da0s1f /mnt/mycfcard <-- ok

On 2009-07-23 06:24:17PM +0300, Andriy Gapon wrote:
> on 23/07/2009 17:14 Kevin Oberman said the following:
> > If Linux detects media insertion instantly or Windows detects media
> > insertion instantly (which I can confirm), there is some signal
> > available, so looking at the Linux driver should provide a clue as to
> > what to look for and that can be added to the FreeBSD umass driver. It
> > would be a very desirable addition, but I am not volunteering as I
> > currently don't use such devices. (And, no one would like the terrible
> > code I would write, anyway.)
> 
> Just a note of caution: human "instant" is different from "computer instant".
> If OS driver polls, say, every 0.2 seconds, you won't be able to tell the difference.
> 
> -- 
> Andriy Gapon
> _______________________________________________
> freebsd-stable@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
> To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"

-- 
===========================================================
Peter C. Lai                 | Bard College at Simon's Rock
Systems Administrator        | 84 Alford Rd.
Information Technology Svcs. | Gt. Barrington, MA 01230 USA
peter AT simons-rock.edu     | (413) 528-7428
===========================================================




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20090723153338.GA31463>