From 010988e888a0abbe7118635c1b33d049caae6b29 Mon Sep 17 00:00:00 2001 From: Stefan Nickl Date: Mon, 5 Sep 2005 01:57:46 -0500 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Vojtech Pavlik Signed-off-by: Dmitry Torokhov --- drivers/usb/input/hiddev.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/usb/input/hiddev.c b/drivers/usb/input/hiddev.c index 4c13331b5f41..d32427818af7 100644 --- a/drivers/usb/input/hiddev.c +++ b/drivers/usb/input/hiddev.c @@ -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; -- 2.20.1