Linus has requested that the sysfs rom attribute be changed to require
enabling before it works. echo "0" to the attribute to disable,
echoing anything else enables the rom output. The concern is that
something like a file browser could inadvertently read the attribute
and change the state of the hardware without the user's knowledge.

The attached patch includes the previous patch plus the enabling logic.

[root@smirl 0000:02:02.0]#
[root@smirl 0000:02:02.0]# cat rom
cat: rom: Invalid argument
[root@smirl 0000:02:02.0]# echo "1" >rom
[root@smirl 0000:02:02.0]# hexdump -C -n 20 rom
00000000  55 aa 60 e9 d6 01 00 00  00 00 00 00 00 00 00 00  |U.`.............|
00000010  00 00 00 00                                       |....|
00000014
[root@smirl 0000:02:02.0]# echo "0" >rom
[root@smirl 0000:02:02.0]# hexdump -C -n 20 rom
hexdump: rom: Invalid argument
[root@smirl 0000:02:02.0]#
Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>