This patch causes the usb-storage driver to return an error indication
(DID_ERROR together with SUGGEST_RETRY) when the amount transferred by a
SCSI command is smaller than the "underflow" amount.  Some devices, like
the iRiver H100 series, occasionally transfer 0 bytes with GOOD status.
This change will make the sd driver aware that something unexpected has
happened so it can retry the command.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>