tree 149aa791fe110d309dfcba8db474c2b74e0ed3ca
parent a4f0927ef588cf62bb864707261482c874352942
author John Keeping <john@metanate.com> 1511806540 +0000
committer Felipe Balbi <felipe.balbi@linux.intel.com> 1511867131 +0200

usb: f_fs: Force Reserved1=1 in OS_DESC_EXT_COMPAT

The specification says that the Reserved1 field in OS_DESC_EXT_COMPAT
must have the value "1", but when this feature was first implemented we
rejected any non-zero values.

This was adjusted to accept all non-zero values (while now rejecting
zero) in commit 53642399aa71 ("usb: gadget: f_fs: Fix wrong check on
reserved1 of OS_DESC_EXT_COMPAT"), but that breaks any userspace
programs that worked previously by returning EINVAL when Reserved1 == 0
which was previously the only value that succeeded!

If we just set the field to "1" ourselves, both old and new userspace
programs continue to work correctly and, as a bonus, old programs are
now compliant with the specification without having to fix anything
themselves.

Fixes: 53642399aa71 ("usb: gadget: f_fs: Fix wrong check on reserved1 of OS_DESC_EXT_COMPAT")
Cc: <stable@vger.kernel.org>
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>