tree 064ebbc4e054bb19bb685475bcc07be21d6a1b76
parent 7d25258f69cedc2f2e55eb25ba2e2078060b44f4
author Stefan Nickl <Stefan.Nickl@kontron.com> 1125903466 -0500
committer Dmitry Torokhov <dtor_core@ameritech.net> 1125903466 -0500

Input: HIDDEV - make HIDIOCSREPORT wait IO completion

When trying to make the hiddev driver issue several Set_Report control
transfers to a custom device with 2.6.13-rc6, only the first transfer in a
row is carried out, while others immediately following it are silently
dropped.

This happens where hid_submit_report() (in hid-core.c) tests for
HID_CTRL_RUNNING, which seems to be still set because the first transfer is
not finished yet.

As a workaround, inserting a delay between the two calls to
ioctl(HIDIOCSREPORT) in userspace "solves" the problem.  The
straightforward fix is to add a call to hid_wait_io() to the implementation
of HIDIOCSREPORT (in hiddev.c), just like for HIDIOCGREPORT.  Works fine
for me.

Apparently, this issue has some history:
http://marc.theaimsgroup.com/?l=linux-usb-users&m=111100670105558&w=2

Signed-off-by: Stefan Nickl <Stefan.Nickl@kontron.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>