[nSLUG] Re Card Reader

Rich budman85 at eastlink.ca
Mon Feb 11 02:07:21 AST 2008

Aaron Spanik wrote:
>> usb 2-1: USB disconnect, address 5
>> usb 2-1: new full speed USB device using uhci_hcd and address 6
>> usb 2-1: configuration #1 chosen from 1 choice
>>  uba: uba1
>> usbcore: deregistering interface driver usb-storage
>> Initializing USB Mass Storage driver...
>> usbcore: registered new interface driver usb-storage
>> USB Mass Storage support registered.
>> FAT: bogus number of reserved sectors
>> VFS: Can't find a valid FAT filesystem on dev uba
> The "USB Mass Storage support registered." apparently comes
> from /usr/src/linux/drivers/usb/storage/usb.c (at least on my OpenSUSE
> 10.3 system running kernel 2.6.22), which is the usb-storage.ko kernel
> module.  The usb-storage.ko module, to my knowledge, links into the
> SCSI layer in the kernel, which generally assigns devices like /dev/sd?
> to USB disk devices as well as SCSI disk devices.
The hubs are using usb_storage, but any cards or ipods, etc, will now 
use the ub driver.

> The output above specifies /dev/uba, though, and you specify that the
> problem has been labelled a bug in the ub driver, which I assume
> indicates ub.ko, also known as the "Low Performance USB Block Driver."
> The ub driver, according to the link posted by Mike Spencer in
> another post (http://gentoo-wiki.com/HOWTO_USB_Mass_Storage_Device), is
> to be avoided if at all possible.
> Do you have both the ub and usb-storage drivers built-in or loaded
> simultaneously as modules in your system?  There is apparently also
> something called "libusual" which can mitigate runtime conflicts
> between ub and usb-storage, which implies that the two tend to conflict.
I'm running Slackware Current, 12.1 beta. 
Hal has had a work over to use the ub module to help ease device updates.
I'm working with Pete Zaitcev, the developer of the ub module.  He had a 
new patch for me to try, no luck so far.

Here is a link to see why they are now using ub for USB hot plug devices 
like Ram Drives, Card Readers, etc.
 From what I can see, its to improve driver turnover time as usb_storage 
is very complex.
Eventually, the fixes in the ub driver should migrate to the usb_storage 
driver, but because
the ub driver is working so well, they don't want to eliminate it any 
time soon.

Re: Why use the ub driver?
Pete Zaitcev zaitcev at redhat.com 

> With udev and hal in the mix, it may be that your system can't use
> usb-storage.ko for the device, so ub.ko is being loaded.  Or it may be
> that udev is set to name all USB Storage Devices, regardless of driver,
> to /dev/ub?.  
In 12.0, hal used usb_storage and the scsi driver, as you explained above.
That worked fine, but I guess has it limitations to new hardware.
Yes, ub is the new naming format in 12.1 (I think all distros may be 
migrating to that in future releases).
I think the latest version of hal and udev require the new device naming 

Good thing to read the  CHANGES_AND_HINTS.TXT file in Slackware current.
It explains a few major changes (fix for mysql, udev leveling scripts, 
hplip no longer daemon, glibc update, lots of Hal changes)

> Anyways, more grist for the mill; I'm curious how it all shakes out.
sure - i'll send updates once they resolve.
Its very close to working, seems hal can see the reader, but not the 
memory cards.


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