[ALUG] USB device, detected OK but nothing appears, what next?

[Steve Fosdick]

On Tue, 2009-11-24 at 21:56 +0000, Chris G wrote:
> I have a new memory card reader which 'does all the right things' when
> you plug it in but nothing appears on my desktop.  An older, very
> similar, device works OK and the memory card appears as a drive on my
> desktop.
> 
> How does one diagnose this sort of problem?  When I plug in the reader
> (and card) that doesn't work I see the following in syslog:-
> 
> Nov 24 21:49:16 chris kernel: [34956.231212] hub 2-1:1.0: USB hub found
> Nov 24 21:49:16 chris kernel: [34956.231361] hub 2-1:1.0: 3 ports detected
> Nov 24 21:49:17 chris kernel: [34956.508106] usb 2-1.1: new high speed USB device using ehci_hcd and address 8
> Nov 24 21:49:17 chris kernel: [34956.600669] usb 2-1.1: configuration #1 chosen from 1 choice
> Nov 24 21:49:17 chris kernel: [34956.600753] hub 2-1.1:1.0: USB hub found
> Nov 24 21:49:17 chris kernel: [34956.600887] hub 2-1.1:1.0: 3 ports detected
> Nov 24 21:49:17 chris kernel: [34956.881611] usb 2-1.1.1: new high speed USB device using ehci_hcd and address 9
> Nov 24 21:49:17 chris kernel: [34957.031679] usb 2-1.1.1: configuration #1 chosen from 1 choice
> Nov 24 21:49:17 chris kernel: [34957.031947] scsi7 : SCSI emulation for USB Mass Storage devices
> Nov 24 21:49:17 chris kernel: [34957.032114] usb-storage: device found at 9
> Nov 24 21:49:17 chris kernel: [34957.032116] usb-storage: waiting for device to settle before scanning
> Nov 24 21:49:22 chris kernel: [34962.033925] usb-storage: device scan complete
> Nov 24 21:49:22 chris kernel: [34962.043387] scsi 7:0:0:0: Direct-Access     Generic  Ultra HS-SD/MMC  1.82 PQ: 0 ANSI: 0
> Nov 24 21:49:22 chris kernel: [34962.058283] sd 7:0:0:0: [sdc] Attached SCSI removable disk
> Nov 24 21:49:22 chris kernel: [34962.058361] sd 7:0:0:0: Attached scsi generic sg3 type 0

Chris,

That output looks fine as far as it goes but doesn't show the kernel
recognising the partition table and figuring what partitions are
available.

If I insert a memory card into my netbook which has a built-in card
reader I get:

Nov 24 23:40:44 valouise kernel: [   77.046367] sd 6:0:0:0: [sdb]
2012160 512-byte logical blocks: (1.03 GB/982 MiB)
Nov 24 23:40:44 valouise kernel: [   77.047220] sd 6:0:0:0: [sdb]
Assuming drive cache: write through
Nov 24 23:40:44 valouise kernel: [   77.049610] sd 6:0:0:0: [sdb]
Assuming drive cache: write through
Nov 24 23:40:44 valouise kernel: [   77.049631]  sdb: sdb1

The last line indicates finding a single partition.  Is there a
partition table on the media or has the file system been build on the
whole media with no partition table (as was done with floppies)?  The
kernel will work fine with that and you could mount the /dev/sdc device
but I suspect whatever automounts the media may not do so in that case.

Regards,
Steve.