problems with scsi disk, scsi generic, and compact flash reader

problems with scsi disk, scsi generic, and compact flash reader

[Chris Friesen]

I have a 2.6.0-test6 kernel with the jumpshot card reader.  I can
compile the generic scsi driver no problem, and when I insert the flash
card I get the following log entry:

Oct  9 20:33:30 doug kernel: hub 2-1:1.0: new USB device on port 2,
assigned address 4
Oct  9 20:33:30 doug kernel: scsi1 : SCSI emulation for USB Mass Storage
devices
Oct  9 20:33:30 doug kernel:   Vendor: Lexar     Model: Jumpshot USB CF
   Rev: 0001
Oct  9 20:33:30 doug kernel:   Type:   Direct-Access
   ANSI SCSI revision: 02
Oct  9 20:33:30 doug kernel: Attached scsi generic sg1 at scsi1, channel
0, id 0, lun 0,  type 0


When I try and load the sd_mod module, that terminal just simply freezes
and I can't break out.  Similarly, if I compile scsi disk support right
into the kernel, it sits forever at boot time.  I have the following
options set in my .config.

#
# SCSI device support
#
CONFIG_SCSI=y
CONFIG_SCSI_PROC_FS=y

#
# SCSI support type (disk, tape, CD-ROM)
#
CONFIG_BLK_DEV_SD=m
# CONFIG_CHR_DEV_ST is not set
# CONFIG_CHR_DEV_OSST is not set
# CONFIG_BLK_DEV_SR is not set
CONFIG_CHR_DEV_SG=y

#
# Some SCSI devices (e.g. CD jukebox) support multiple LUNs
#
# CONFIG_SCSI_MULTI_LUN is not set
# CONFIG_SCSI_REPORT_LUNS is not set
CONFIG_SCSI_CONSTANTS=y
CONFIG_SCSI_LOGGING=y


Any ideas what's going on?

Thanks,
Chris

Re: problems with scsi disk, scsi generic, and compact flash reader

[Douglas Gilbert]

Chris Friesen wrote:
> 
> I have a 2.6.0-test6 kernel with the jumpshot card reader.  I can
> compile the generic scsi driver no problem, and when I insert the flash
> card I get the following log entry:
> 
> Oct  9 20:33:30 doug kernel: hub 2-1:1.0: new USB device on port 2,
> assigned address 4
> Oct  9 20:33:30 doug kernel: scsi1 : SCSI emulation for USB Mass Storage
> devices
> Oct  9 20:33:30 doug kernel:   Vendor: Lexar     Model: Jumpshot USB CF
>   Rev: 0001
> Oct  9 20:33:30 doug kernel:   Type:   Direct-Access
>   ANSI SCSI revision: 02
> Oct  9 20:33:30 doug kernel: Attached scsi generic sg1 at scsi1, channel
> 0, id 0, lun 0,  type 0
> 
> 
> When I try and load the sd_mod module, that terminal just simply freezes
> and I can't break out.  Similarly, if I compile scsi disk support right
> into the kernel, it sits forever at boot time. 

Chris,
The compact flash probably doesn't like a MODE SENSE
command it is being sent by the sd driver. When sd is
a module then if your other (pseudo) terminals are alive
after 'modprobe sd_mod' locks up then perhaps you could
try 'ps -eo cmd,wchan' on another terminal and report
the result for that modprobe.

Some patches went into sd recently (and more are being discussed)
to lower the MODE SENSE traffic during sd initialization. There
is a very wide range of devices that use the scsi command set
and there is no easy way to know during scan/initialization
how well a device will handle some commands (scsi_level ??).

Another thing you could do is fetch sg3_utils from
http://www.torque.net/sg and report the result of
'sg_modes -a /dev/sg1'. That will report the MODE SENSE
commands the device claims to support. [BTW Run 'sg_modes'
before you try to 'modprobe sd_mod'.]

Doug Gilbert