Re: USB card reader

["A.J. Bonnema" <abonnema xs4all nl>]

Taylor, ForrestX wrote:
> > > You may have a problem like I did this weekend:
> > >
> > > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=110653
> > >
> > > The Fedora/Red Hat kernels don't have multi-LUN support (basically one
> > > device with multiple disks).  You can manually add the LUNs in /proc:
> > >
> > > echo "scsi-add-single-device 0 0 0 1" > /proc/scsi/scsi
> > > echo "scsi-add-single-device 0 0 0 2" > /proc/scsi/scsi
> > > echo "scsi-add-single-device 0 0 0 3" > /proc/scsi/scsi
> > >
> > > See if that helps.
> > >
> > > Forrest

> > What I wonder about is, how did you find the error and how did you find 
> > the statements to correct it?
>
>
> It took me an hour or two of googling to make some sense out of it. 
> Originally I was trying to mount /dev/sda1, because I thought that it
> would only see one slot at a time.  I eventually found Question 9 under
> Trouble Shooting from the FAQ on http://www.linux-usb.org/.  From there
> it was just testing and documentation.

<arrgh> I think I have seen this faq and this question but I had no idea 
what a multi-lun is, so I didn't understand it (now I do ...)

> I created a patch for USB hotplug that should look at your scsi devices
> and send the lines automatically.  If you get a chance, try it out (and
> remove the scsi-add-single-device lines you may have added elsewhere.

I did. It works. However, in stead of unplugging it (I'm lazy) I 
restarted Linux and, low and behold ... the device got (completely) 
recognized. Congratulations.

Something strange though... When I first restarted, the kernel started 
booting, gave a few sda, sdb, sdc detection errors (no disk in device), 
and restarted againg. As I could not reproduce the error, I suppose I 
can't tell any more than that.

Anyway, probably it's safe to submit.

> To use this patch, su to root and cd to /etc/hotplug.  Make a backup
> copy of hotplug.functions (cp hotplug.functions hotplug.functions.orig),
> and run patch:
> patch -p2 < /path/to/hotplug-multilun.patch
>
> Unplug the USB card reader, and plug it back in, and then look at
> /proc/scsi/scsi to see if you have more than one device for you card
> reader.  I have only tested it a few times, but it works for me.  Let me
> know how it works for you.  If it works for you, I'll post it on
> bugzilla.
>
> Forrest
>
>
> ------------------------------------------------------------------------
>
> --- /etc/hotplug/hotplug.functions.orig	2003-11-24 12:12:27.000000000 -0800
> +++ /etc/hotplug/hotplug.functions	2003-11-24 12:23:16.000000000 -0800
> @@ -171,6 +171,19 @@
>  	fi
>  	if echo "$MODULE" | grep -q "usb-storage" > /dev/null 2>&1 ; then
>  	    [ -x /usr/sbin/updfstab ] &&  /usr/sbin/updfstab
> +
> +	    # Grab the scsi variables from /proc/scsi/scsi
> +	    SCSI=`grep -B 1 "USB Card Reader" /proc/scsi/scsi | grep Host | awk '{print $2}' | awk -Fscsi '{print $2}'`
> +	    CHANNEL=`grep -B 1 "USB Card Reader" /proc/scsi/scsi | grep Host | awk '{print $4}' | bc -l`
> +	    ID=`grep -B 1 "USB Card Reader" /proc/scsi/scsi | grep Host | awk '{print $6}' | bc -l`
> +
> +	    mesg Adding multi-LUN support
> +	    # Add LUNs 1-15
> +	    i=1
> +	    while [[ $i -lt 16 ]];do
> +	    echo "scsi-add-single-device $SCSI $CHANNEL $ID $i" >> /proc/scsi/scsi
> +	    i=`echo "$i+1" | bc -l`
> +	    done
>  	fi
>      done
>  }


Anyway, Forrest: thanks for your help. I am indebted to you.

Guus.
--
A.J. Bonnema, Leiden The Netherlands,
user #328198 (Linux Counter)