usb-storage: Accept 8020i-protocol commands longer than 12 bytes
authorAlan Stern <stern@rowland.harvard.edu>
Tue, 25 Oct 2011 14:50:58 +0000 (10:50 -0400)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 15 Nov 2011 01:05:03 +0000 (17:05 -0800)
commit2f640bf4c94324aeaa1b6385c10aab8c5ad1e1cf
tree498f41d40a6d6d34f93ecf7420fc7145fcd70d12
parent0d145d7d4a241c321c832a810bb6edad18e2217b
usb-storage: Accept 8020i-protocol commands longer than 12 bytes

The 8020i protocol (also 8070i and QIC-157) uses 12-byte commands;
shorter commands must be padded.  Simon Detheridge reports that his
3-TB USB disk drive claims to use the 8020i protocol (which is
normally meant for ATAPI devices like CD drives), and because of its
large size, the disk drive requires the use of 16-byte commands.
However the usb_stor_pad12_command() routine in usb-storage always
sets the command length to 12, making the drive impossible to use.

Since the SFF-8020i specification allows for 16-byte commands in
future extensions, we may as well accept them.  This patch (as1490)
changes usb_stor_pad12_command() to leave commands larger than 12
bytes alone rather than truncating them.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Simon Detheridge <simon@widgit.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/storage/protocol.c