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Input: HIDDEV - make HIDIOCSREPORT wait IO completion

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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>
This commit is contained in:
Stefan Nickl 2005-09-05 01:57:46 -05:00 committed by Dmitry Torokhov
parent 7d25258f69
commit 010988e888
1 changed files with 1 additions and 0 deletions
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1
drivers/usb/input/hiddev.c
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@ -507,6 +507,7 @@ static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd
return -EINVAL;
hid_submit_report(hid, report, USB_DIR_OUT);
hid_wait_io(hid);
return 0;